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.

A231228 Number of permutations of [n] with exactly one occurrence of one of the consecutive patterns 123, 1432, 2431, 3421.

Table of values

n a(n)
0 0
1 0
2 0
3 1
4 9
5 59
6 358
7 2235
8 14658
9 103270
10 778451
11 6315499
12 54733657
13 507655301
14 5003179539
15 52430810493
16 580611272956
17 6796733911852
18 83658527086447
19 1083027034959367
20 14678725047527255
21 208344799726820123
22 3084495765476262875
23 47646333262275943521

List of values

[0, 0, 0, 1, 9, 59, 358, 2235, 14658, 103270, 778451, 6315499, 54733657, 507655301, 5003179539, 52430810493, 580611272956, 6796733911852, 83658527086447, 1083027034959367, 14678725047527255, 208344799726820123, 3084495765476262875, 47646333262275943521]

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

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