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.

A151597 Number of permutations of 4 indistinguishable copies of 1..n arranged in a circle with exactly 2 adjacent element pairs in decreasing order.

Table of values

n a(n)
1 0
2 36
3 606
4 4744
5 30850
6 186924
7 1092966
8 6248976
9 35154954
10 195310900
11 1074216814
12 5859372696
13 31738278546
14 170898434364
15 915527340150
16 4882812495904
17 25939941401626
18 137329101557316
19 724792480462974
20 3814697265618600
21 20027160644524194
22 104904174804679756

List of values

[0, 36, 606, 4744, 30850, 186924, 1092966, 6248976, 35154954, 195310900, 1074216814, 5859372696, 31738278546, 170898434364, 915527340150, 4882812495904, 25939941401626, 137329101557316, 724792480462974, 3814697265618600, 20027160644524194, 104904174804679756]