Mild Narcissistic Constants

The basic idea for this took shape after thinking about Mike Keith's wild narcissistic numbers. Can we come up with any criterion that evinces self-reference when numbers are expressed in simple-continued-fraction form? I had already concluded that Khinchin's constant was itself a kind of strong narcissistic constant, insofar as the geometric mean of its constituent parts is the number itself. Technically, I suppose, this remains to be proved.

In 1935, A.Ya. Khinchin showed that - for almost all irrationals - the frequency of occurrence of a given number 'n' in its (infinite) simple continued fraction expansion is (Log[(n + 1)^2] - Log[(n + 1)^2 - 1])/Log[2] ("Log" here being the "natural" logarithm, i.e., to the base 'e'). In fact, Mathematica shows Sum[Log[(n + 1)^2/((n + 1)^2 - 1)]/Log[2], {n, 1, Infinity}] == 1.

The frequencies are (approximately) {.415037, .169925, .0931094, .0588937, .040642, .0297473, .0227201, .0179219, .0144996, ...}. In continued fraction form (28 terms of each the first 120 MNCs):

#\Term> 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
1 0 2 2 2 3 1 5 2 23 2 2 1 1 55 1 4 3 1 1 15 1 9 2 5 7 1 1 4
2 0 5 1 7 1 2 4 11 1 2 2 3 27 1 9 1 1 3 7 1 19 1 10 3 1 3 2 17
3 0 10 1 2 1 5 1 1 6 1 10 1 1 3 1 10 1 1 2 5 2 1 25 4 1 1 1 3
4 0 16 1 48 2 1 1 1 4 1 3 1 4 1 6 3 2 1 2 15 2 11 4 1 1 8 2 1
5 0 24 1 1 1 1 7 4 18 2 1 1 48 1 5 1 3 1 3 1 1 1 1 1 2 1 1 2
6 0 33 1 1 1 1 1 1 4 1 20 3 1 1 2 1 24 1 50 2 4 1 2 1 40 1 1 1
7 0 44 71 1 3 12 4 1 1 2 4 1 2 1 2 5 1 1 2 15 1 17 1 2 204 1 1 4
8 0 55 1 3 1 16 12 3 197 4 6 2 2 31 1 7 3 25 1 3 23 2 1 5 1 1 1 1
9 0 68 1 29 1 4 1 7 4 1 1 1 39 1 2 104946 3 4 1 2 2 1 8 20 1 1 1 7
10 0 83 1 1 10 42 5 4 1 1 1 6 3 1 3 1 4 38 1 2 1 2 30 2 1 2 5 4
11 0 99 2 6 1 9 27 3 1 3 1 8 10 1 2 1 1 5 1 2 1 1 1 11 1 2 22 4
12 0 116 1 3 1 7 7 1 1 2 1 2 1 7 1 1 1 2 1 4 1 1 1 1 16 5 1 6
13 0 135 1 1 24 1 1 4 9 2 1 2 1 2 25 1 3 1 1 1 1 1 8 40 2 11 1 9
14 0 155 1 1 1 1 2 1 17 18 1 2 3 2 2 1 173 9 16 1 5 4 3 2 9 2 1 1
15 0 177 10 8 1 4 2 7 11 3 3 1 1 5 4 2 1 5 1 3 1 6 1 20 2 1 8 1
16 0 199 1 35 1 2 2 11 2 24 1 5 1 3 1 4 9 3 4 19 1 1 2 1 1 8 2 8
17 0 224 4 3 2 2 2 1 5 2 2 1 6 1 2 1 12 2 2 31 1 2 1 1 48 1 1 1
18 0 249 1 7 3 2 2 1 17 1 1 1 1 4 1 1 4 14 1 2 2 2 2 1 6 1 6 3
19 0 276 1 10 2 1 1 1 1 5 90 1 1 2 2 2 3 1 1 1 2 2 1 2 3 17 1 11
20 0 305 3 51 1 3 1 11 39 32 1 3 7 1 1 1 1 2 1 1 6 3 2 1 1 1 1 1
21 0 335 7 3 11 4 10 78 1 30 1 1 1 4 2 1 46 2 3 1 1 1 3 1 2 1 2 6
22 0 366 3 21 4 1 3 2 4 9 4135 1 166 2 5 5 1 2 18 2 1 1 60 1 29 1 2 28
23 0 398 1 9 1 1 1 5 1 16 1 7 1 1 6 1 2 1 5 1 15 1 5 3 2 3 3 1
24 0 432 1 6 1 2 2 6 1 1 1 2 2 1 12 2 26 1 21 8 1 9 4 1 1 2 3 2
25 0 468 4 1 1 8 2 1 10 128 5 1 1 1 2 1 2 2 4 10 1 18 1 1 13 1 3 2
26 0 504 1 22 1 1 1 1 4 3 3 1 14 1 1 7 1 15 3 1 1 1 3 15 1 1 4 4
27 0 543 12 2 1 1 2 12 13 2 2 15 15 1 1 1 1 2 3 1 2 3 2 1 1 2 5 3
28 0 582 1 1 2 3 1 1 1 9 5 1 8 7 3 71 7 7 2 2 2 8 2 4 2 1 8 1
29 0 623 2 17 7 2 1 36 1 1 2 1 4 2 3 2 1 2 1 65 1 14 1 1 1 2 14 6
30 0 665 1 3 3 3 1 5 1 1 3 2 1 8 1 2 1 3 6 2 1 7 5 1 2 5 6 1
31 0 709 2 3 2 2 3 7 2 1 1 3 6 8 1 1 16 1 9 1 1 1 3 4 1 5 4 3
32 0 754 2 26 4 17 2 9 1 4 2 1 17 2 1 7 3 1 1 3 1 1 2 5 3 1 12 1
33 0 800 1 13 1 1 1 1 17 1 1 1 1 1 1 1 2 11 3 4 1 2 4 5 1 3 2 1
34 0 848 1 3 6 1 20 1 6 3 1 3 1 2 1 14 5 1 1 3 1 1 2 1 42 2 2 10
35 0 897 1 34 1 7 4 1 18 5 1 1 5 1 9 10 2 1 3 1 330 1 1 1 1 4 1 3
36 0 948 1 1 2 1 45 15 1 13 2 2 1 3 2 2 3 2 9 1 52 2 71 1 1 6 11 1
37 0 1000 1 1 3 1 4 2 4 1 56 1 1 2 1 34 3 1 1 2 12 1 5 1 2 51 1 1
38 0 1053 1 13 2 1 30 4 6 3 2 1 2 2 2 2 1 25 1 2 1 3 7 1 1 15 1 2
39 0 1108 1 2 4 1 2 50 1 1 2 1 4 12 8 33 26 5 36 1 5 2 2 9 3 1 1 2
40 0 1164 1 5 59 30 1 2 1 5 1 3 1 4 1 1 7 1 2 4 3 1 4 71 3 2 5 1
41 0 1222 2 1 2 1 5 4 12 3 5 5 16 1 89 1 1 5 1 20 20 4 2 1 1 10 1 9
42 0 1281 3 1 1 5 1 5 3 5 1 6 1 1 3 1 6 1 1 1 1 2 1 7 2 3 1 4
43 0 1341 1 1 2 2 1 1 8 2 9 3 1 1 2 10 6 4 2 1 1 1 1 1 6 1 2 4
44 0 1403 3 1 1 1 1 1 1 2 3 1 4 2 2 3 5 13 1 103 1 2 1 10 1 2 13 2
45 0 1466 2 1 5 31 1 6 5 1 2 5 1 14 1 1 1 1 1 2 3 5 1 5 1 1 10 1
46 0 1530 1 4 2 2 1 1 1 7 3 4 1 1 1 2 2 3 1 1 1 10 3 2 1 1 24 1
47 0 1596 1 1 1 50 1 2 1 7 4 10 3 4 1 5 1 2 1 9 1 10 2 29 1 2 1 5
48 0 1663 1 8 1 45 6 2 2 1 3 32 1 2 33 2 1 8 1 1 2 8 6 13 1 1 1 3
49 0 1732 1 1 11 4 1 4 1 8 2 5 117 1 15 1 1 2 2 20 3 1 1 2 3 1 5 1
50 0 1802 1 1 8 18 191 1 5 2 1 50 4 2 1 7 1 3 25 1 7 1 17 1 21 1 3 1
51 0 1873 1 12 19 2 1 2 1 6 1 14 3 1 6 3 1 1 2 1 2 1 2 3 4 4 1 9
52 0 1946 1 2 2 1 1 1 9 1 2 1 3 1 4 4 1 6 4 1 15 23 1 13 1 1 14 1
53 0 2020 1 6 1 2 1 1 1 43 1 1 1 10 1 1 19 6 2 4 26 1 16 11 1 2 1 2
54 0 2096 2 2 1 3 2 2 2 2 1 3 9 14 4 2 3 2 1 1 1 8 1 1 3 2 2 3
55 0 2173 2 1 3 12 16 1 2 1 14 1 7 5 1 2 1 9 3 12 1 1 4 4 7 1 6 1
56 0 2251 1 2 4 1 2 1 2 1 10 10 2 4 2 2 21 1 14 5 2 1 1 6 1 3 2 2
57 0 2331 2 2 75 1 5 2 1 3 1 2 9 1 1 1 1 1 1 1 1 1 12 1 2 1 1 2
58 0 2412 2 198 1 3 7 1 15 14 31 1 1 1 2 6 1 3 3 3 2 30 1 9 2 1 1 4
59 0 2494 1 58 1 2 1 4 1 2 4 1 16 5 3 1 117 1 22 4 1 1 1 3 1 6 2 4
60 0 2578 1 5 1 5 1 3 1 1 1 1 1 16 1 1 1 6 1 2 66 2 5 2 1 11 24 1
61 0 2664 8 1 197 7 11 3 3 2 1 1 1 14 1 1 1 1 25 2 5 2 2 25 5 1 10 6
62 0 2750 1 3 13 2 2 1 2 4 8 1 2 3 10 1 4 17 1 2 25 1 3 1 9 1 5 2
63 0 2838 1 3 1 1 1 2 1 6 1 79 1 2 7 1 10 1 1 1 1 2 5 1 6 1 112 4
64 0 2928 4 1 158 1 4 2 2 1 1 4 99 1 3 5 8 1 1 9 2 1 3 3 1 1 4 1
65 0 3019 394 1 299 12 4 1 5 1 1 2 3 3 11 1 2 5 1 54 2 1 1 5 1 1 7 1
66 0 3111 5 4 3 2 1 4 5 8 1 3 1 1 9 5 2 1 494 1 4 1 2 1 1 2 4 1
67 0 3204 1 3 3 1 1 1 22 1 2 1 1 2 7 4 2 1 2 2 12 1 61 1 1 1 293 13
68 0 3299 1 2 1 1 1 62 15 4 2 5 1 2 9 1 3 1 1 3 1 2 26 1 4 2 2 1
69 0 3396 13 2 2 7 1 2 3 3 5 22 1 4 4 1 10 1 1 1 3 4 3 1 1 1 5 1
70 0 3493 1 4 4 1 1 2 3 3 2 1 5 2 3 1 1 3 1 2 7 2 13 5 3 4 1 9
71 0 3592 1 12 1 28 1 2 2 4 1 4 1 5 4 2 1 1 1 1 3 1 3 11 1 15 1 6
72 0 3693 2 3 3 44 1 7 2 3 4 54 1 1 1 1 1 1 1 3 1 2 5 1 100 1 20 1
73 0 3795 3 18 3 7 1 4 1 2 1 7 18 2 1 8 1 2 19 78 5 1 4 8 1 5 2 1
74 0 3898 1 1 1 1 5 1 2 1 7 2 3 1 5 2 3 1 1 1 1 2 8 2 1 1 2 14
75 0 4003 3 1 2 6 1 1 4 1 5 1 1 1 1 1 2 15 1 2 1 1 1 1 1 1 2 3
76 0 4109 3 10 2 8 2 1 1 1 1 1 1 6 2 5 1 3 5 1 1 4 1 1 24 2 2 5
77 0 4216 1 3 5 1 1 76 1 1 1 2 2 2 19 1 1 1 1 3 1 2 1 10 1 1 14 13
78 0 4325 1 1 2 2 3 1 4 1 2 18 1 3 210 2 3 1 52 3 1 2 15 34 7 5 1 2
79 0 4435 1 3 1 7 1 5 2 4 13 1 1 32 1 62 4 1 3 3 1 5 4 1 2 2 2 1
80 0 4547 2 1 1 4 2 3 1 15 16 1 430 2 3 2 1 2 1 1 24 1 8 1 2 4 2 1
81 0 4660 2 1 1 1 260 4 1 3 14 1 9 1 1 66 1 3 3 11 6 1 28 3 1 259 1 2
82 0 4774 1 2 1 10 3 3 4 1 3 3 1 82 1 10 13 1 9 2 4 41 41 14 1 1 2 4
83 0 4890 2 3299 1 467 2 4 1 2 3 1 1 5 1 1 23 1 57 1 15 2 1 1 1 1 3 1
84 0 5007 1 1 1 3 1 4 32 198 1 2 22 4 29 1 1 2 24 1 2 2 1 1 1 1 3 1
85 0 5126 5 1 7 1 1 2 2 2 2 1 2 5 2 1 7 2 15 9 1 2 1 1 8 2 2 1
86 0 5246 11 1 5 2 2 1 4 1 1 4 5 17 2 2 5 3 4 3 1 7 1 1 1 1 2 4
87 0 5367 2 1 1 2 9 1 2575 5 16 1 1 22 2 1 33 3 1 6 9 1 1 92 11 1 4 636
88 0 5490 13 1 5 2 1 1 2 1 1 1 7 1 1 1 28 2 7 183 5 1 2 1 1 5 2 1
89 0 5614 6 1 6 1 1 1 2 1 1 1 2 1 1 1 22 12 48 1 3 4 4 2 1 1 1 2
90 0 5739 1 1 1 1 7 16 1 1 4 4 2 1 2 4 1 6 1 1 1 28 2 2 1 34 1 6
91 0 5866 2 4 1 1 1 1 1 1 1 2 2 57 2 3 1 3 2 3 3 11 1 3 3 3 1 2
92 0 5994 1 2 6 3 5 8 10 3 24 1 5 13 1 2 1 26 2 1 2 2 2 7 8 1 2483 3
93 0 6124 3 3 4 1 16 1 1 4 1 2 4 1 1 1 1 3 1 1 2 3 1 1 1 6 13 1
94 0 6255 3 3 1 5 2 1 8 1 2 1 4 2 4 1338 4 1 1 7 1 2 1 2 33 1 22 1
95 0 6387 1 2 3 4 3 9 38 1 10 1 1 1 3 1 3 1 1 4 11 2 1 1 5 2 1 2
96 0 6521 2 9 1 1 2 17 1 6 1 7 14 9 1 8 1 1 2 10 1 1 1 1 1 1 1 1
97 0 6656 1 1 1 3 2 1 13 1 2 2 1 70 1 4 46 1 1 7 2 4 2 5 1 4 1 6
98 0 6793 5 3 2 2 2 6 1 7 1 7 1 1 10 1 2 52 1 5 1 1 3 16 1 17 1 1
99 0 6931 7 1 68 5 4 3 1 1 2 13 1 1 36 265 1 6 1 1 73 8 1 1 3 4 2 21
100 0 7070 2 4 3 2 4 6 23 1 4 67 1 2 1 28 1 1 1 18 1 1 1 1 1 20 2 5
101 0 7211 6 2 1 1 1 1 1 1 3 3 381 4 1 2 4 9 2 3 4 1 11 4 2 1 2 6
102 0 7353 3 1 32 1 6 5 1 1 4 1 2 3 2361 7 1 2 2 1 6 4 1 4 3 1 7 4
103 0 7496 1 2 1 2 1 605 1 3 2 2 2 4 2 1 9 333 33 2 2 2 1 2 1 3 1 2
104 0 7641 1 1 1 1 36 4 1 9 1 2 66 4 2 4 1 6 1 1 5 9 2 3 1 4 1 14
105 0 7787 1 5 1 9 2 1 11 9 1 1 3 1 11 2 6 1 2 1 23 2 4 1 1 1 4 118
106 0 7935 2 54 1 19 1 4 1 3 2 83 1 6 1 12 1 1 1 8 3 2 1 3 1 1 1 1
107 0 8084 1 1 10 1 3 1 5 1 17 1 1 1 1 10 7 38 1 3 12 3 2 1 3 2 3 2
108 0 8234 1 14 2 2 18 1 1 1 73 2 2 1 1 1 4 249 89 24 4 1 3 1 2 6 5 8
109 0 8386 1 2 1 3 4 3 3 13 5 1 47 2 1 1 2 1 3 3 3 5 1 6 1 5 2 1
110 0 8539 1 11 2 9 8 13 1 2 2 2 1 1 2 1 156 1 8 12 1 16 2 4 1 60 6 2
111 0 8694 2 29 2 5 2 1 58 2 7 15 1 2 1 1 2 6 2 1 3 9 3 6 1 5 840 27
112 0 8850 2 4 2 10 2 3 1 2 1 33 2 1 4 3 1 1 11 12 5 2 5 1 6 3 2 2
113 0 9007 1 3 1 6 13 1 1 1 1 2 1 23 2 1 4 5 4 1 9 3 3 3 3 1 2 10
114 0 9166 1 1 9 1 1 4 1 9 1 3 1 2 17 7 1 4 1 1 2 1 9 1 1 1 3 44
115 0 9326 1 1 1 3 1 4 2 5 7 20 3 1 2 3 1 4 6 1 7 2 10 15 2 2 4 2
116 0 9488 6 1 7 1 15 1 4 7 2 2 3 9 5 2 1 2 3 2 2 1 2 16 2 3 25 10
117 0 9651 28 1 3 3 1 8 1 1 3 2 4 1 3 1 2 3 10 1 4 1 1 2 1 1 5 3
118 0 9815 3 4 1 1 3 2 1 1 5 3 5 1 39 3 3 1 1 8 1 1 7 4 13 13 2 1
119 0 9980 1 35 1 3 1 7 2 1 6 1 3 1 35 32 2 1 1 1 11 1 31 20 2 1 1 12
120 0 10148 46 1 26 1 1 4 1 12 1 3 1 1 1 3 2 32 1 4 44 10 1 5 6 1 9 1

We expect, in the n-th mild narcissistic constant (MNC), the frequency of occurrence of the number 'n' to be equal to the constant itself!

Another way of looking at this is to consider term-1 of the constants: efop = {2, 5, 10, 16, 24, 33, 44, 55, 68, 83, 99, 116, 135, 155, 177, 199, 224, 249, 276, 305, 335, 366, 398, 432, 468, 504, 543, 582, 623, 665, 709, 754, 800, 848, 897, 948, 1000, 1053, 1108, 1164, 1222, 1281, 1341, 1403, 1466, 1530, 1596, 1663, 1732, 1802, 1873, 1946, 2020, 2096, 2173, 2251, 2331, 2412, 2494, 2578, 2664, 2750, 2838, 2928, 3019, 3111, 3204, 3299, 3396, 3493, 3592, 3693, 3795, 3898, 4003, 4109, 4216, 4325, 4435, 4547, 4660, 4774, 4890, 5007, 5126, 5246, 5367, 5490, 5614, 5739, 5866, 5994, 6124, 6255, 6387, 6521, 6656, 6793, 6931, 7070, 7211, 7353, 7496, 7641, 7787, 7935, 8084, 8234, 8386, 8539, 8694, 8850, 9007, 9166, 9326, 9488, 9651, 9815, 9980, 10148, ...}. As a first approximation, the inverse of each of these terms is equal to its MNC. The values represent then, if you will, the expected first-occurrence position-numbers of 'n' in their associated MNCs.

Mathematics, alas, is a tad chaotic... Here are the actual first-occurrence position-numbers in the (first 120) MNCs: afop = {5, 5, 13, 8, 14, 66, 105, 168, 52, 4, 23, 176, 61, 159, 161, 42, 53, 455, 185, 159, 417, 112, 166, 32, 159, 291, 271, 1361, 1122, 451, 1215, 1403, 397, 628, 1786, 1101, 1322, 417, 61, 3472, 1290, 170, 2087, 76, 3237, 1868, 1991, 2179, 430, 11, 6111, 7588, 167, 4093, 7807, 1942, 2913, 118, 2072, 1280, 863, 1675, 2318, 8476, 6444, 3067, 658, 3741, 5389, 738, 223, 504, 90, 210, 1312, 3148, 1237, 3683, 801, 2800, 1543, 13, 7400, 12462, 17354, 536, 2785, 7952, 816, 6316, 13760, 2399, 13081, 5776, 10165, 11941, 3908, 3774, 2502, 14245, 2669, 11001, 3187, 115, 40882, 5438, 15443, 14002, 4357, 3307, 23838, 4686, 17736, 7993, 4159, 9537, 10804, 5995, 5968, 12633, ...}.

We may note that the expected position-number of 2 in the 2nd MNC (term-5) is 2. If we only look at position-numbers that are exact multiples of the n-th MNC's term-1, what is the smallest multiple that brings us to a position containing 'n'?

For n = 1, terms-2,-4,-6,-8,-10 are non-1, but term-12 is a 1, thus the answer is 6. For n = 2, as we have already noted, the answer is 1. For n = 3, terms-10,-20,-30,...,-100 are all non-3, but term-110 is a 3, so the answer is 11. Here is the set of solutions for the first few values of 'n': mult = {6, 1, 11, 28, 16, 2, 88, 8, 208, 61, 20, 48, 76, 661, 308, 206, 256, 142, 144, 570, 4, 1093, 634, 84, 676, 575, 734, 968, 949, 51, 511, 552, 1487, 962, 1258, 875, 2636, 326, 871, ...}. How many terms 'n' have we have encountered when we reach these values? The answer: numb = {3, 1, 10, 23, 16, 1, 79, 5, 233, 63, 25, 33, 70, 643, 314, 211, 229, 135, 164, 604, 4, 1040, 684, 87, 673, 570, 770, 975, 952, 44, 536, 542, 1532, 924, 1262, 872, 2591, 320, 841, ...}. [mult - numb = {3, 0, 1, 5, 0, 1, 9, 3, -25, -2, -5, 15, 6, 18, -6, -5, 27, 7, -20, -34, 0, 53, -50, -3, 3, 5, -36, -7, -3, 7, -25, 10, -45, 38, -4, 3, 45, 6, 30, ...}]

Statistically, it is reasonable to expect the numbers in mult to match those in efop, so, it is unlikely we will we ever see another 1. How about the first number that repeats an existing one? :-)

21 November 1999 © Rarebit Dreams