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.

A221145 a(n) is the number of permutations of n elements with exactly one fixed point and no transpositions.

Table of values

n a(n)
1 1
2 0
3 0
4 8
5 30
6 144
7 1120
8 9120
9 80892
10 808640
11 8908416
12 106889760
13 1389405160
14 19452003648
15 291782125440
16 4668506495744
17 79364583206160
18 1428562661736960
19 27142690917071872
20 542853814698737280
21 11399930105272855776
22 250798462399704792320

List of values

[1, 0, 0, 8, 30, 144, 1120, 9120, 80892, 808640, 8908416, 106889760, 1389405160, 19452003648, 291782125440, 4668506495744, 79364583206160, 1428562661736960, 27142690917071872, 542853814698737280, 11399930105272855776, 250798462399704792320]

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

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