cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A255516 a(n) = A239839(n)/n! where A239839(n) is the number of ordered pairs of permutation functions on n elements where f(f(f(x))) = g(f(g(x))).

Table of values

n a(n)
0 1
1 1
2 2
3 3
4 7
5 13
6 29
7 53
8 126
9 258
10 602
11 1250
12 3031
13 6703
14 16367
15 36698
16 91731
17 214315
18 542225
19 1284284
20 3305371
21 8063704
22 21017382
23 51961767
24 137324923
25 347282636
26 928913378
27 2379051372
28 6439629060
29 16796126329
30 45974995358
31 121341267340
32 335665581851

List of values

[1, 1, 2, 3, 7, 13, 29, 53, 126, 258, 602, 1250, 3031, 6703, 16367, 36698, 91731, 214315, 542225, 1284284, 3305371, 8063704, 21017382, 51961767, 137324923, 347282636, 928913378, 2379051372, 6439629060, 16796126329, 45974995358, 121341267340, 335665581851]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.