sequence joke

[Tanya Khovanova]

So, extending the table of my 20 July 2007 email:

===========
n  a(n)  factorization
3  2     prime
4  3     prime
5  23    prime
6  4     2^2
7  235   5 * 47
8  35    5 * 7
9  26    2 * 13
10 347   prime
11 237   3 * 79
12 58    2 * 29
13 2359  7 * 337
14 349   prime
15 2610  2 * 3^2 * 5 * 29
16 311   prime
17 235711  7 * 151 * 223
18 45712 2^4 * 2857
19 2313  3^2 * 257
20 3813  3 * 31 * 41
21 2614 2 * 1307
22 345915 3^2 * 5 * 7687
23 235915 5 * 29 * 1627
24 716   2^2 * 179
25 2371017 3 * 11 * 71849
26 3417 3 * 17 * 67
27 2561118 2 * 3 * 7 * 17^2 * 211
28 3581119 37 * 96787
29 2319  3 * 773
30 41220 2^2 * 3^2 * 5 * 229
31 237921 3 * 71 * 1117
32 35791321 37 * 967333
33 2561322 2 * 3 * 17 * 25111
34 3423  3 * 7 * 163
35 23101423 97 * 238159
36 824    2^3 * 103
37 2351525 5^2 * 11 * 17 * 503
38 3457111525 5^2 * 7 * 97 * 203659
39 2671126 2 * 1335563
40 391627 prime
41 23927   71 * 337
42 45121728 2^6 * 3 * 235009
43 2351729  17 * 138337
44 3829  7 * 547
45 26710131830 2 * 5 * 41^2 * 757 * 2099
46 3471331 prime
47 2351931 3 * 523 * 1499
48 51932 2^2 * 12983
49 239111433 3^4 * 11 * 43 * 79^2
50 349112033 12119 * 28807
51 2634  2 * 3 * 439
52 3578152135 5 * 79 * 9058613
53 2357152135 5 * 13 * 36263879
54 41236 2^2 * 13^2 * 61
55 23102237 73 * 316469
56 31637 17 * 1861
57 2562338 2 * 23 * 53 * 1051
58 3459132339 3 * 13 * 1229 * 72169
59 2379131739 3^2 * 877 * 301423
60 7811172440 2^3 * 5 * 195279311
61 231141 3 * 77047
62 3452541 3 * 1150847
...




Dear Seqfans,  My old friend Bernardo Recaman Santos just

%I A116700
%S A116700 12,21,23,31,32,34,41,42,43
%N A116700 "Early bird" numbers: write the natural numbers in a string 12345678910111213....
Sequence gives numbers which occur in the string ahead of their natural place.
%C A116700 Based on an idea by Argentinian puzzle creator Jaime Poniachik, these numbers were
MAA.
%e A116700 "12" appears at the start of the string, ahead of its position after "11", so is a
%K A116700 nonn,base,more,nice,new
%O A116700 1,1
%A A116700 Bernardo Recaman Santos (ignotus(AT)hotmail.com), Jul 22 2007

One needs to be a subscriber to have on-line access to
Math Horizons - can anyone get me a copy of the Martin Gardner
article?

Neil