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.

A001268 One-half the number of permutations of length n with exactly 4 rising or falling successions.

Table of values

n a(n)
0 0
1 0
2 0
3 0
4 0
5 1
6 11
7 113
8 1099
9 11060
10 118484
11 1366134
12 16970322
13 226574211
14 3240161105
15 49453685911
16 802790789101
17 13815657556958
18 251309386257874
19 4818622686395380
20 97145520138758844
21 2054507019515346789
22 45484006970415223287
23 1052036480881734378541

List of values

[0, 0, 0, 0, 0, 1, 11, 113, 1099, 11060, 118484, 1366134, 16970322, 226574211, 3240161105, 49453685911, 802790789101, 13815657556958, 251309386257874, 4818622686395380, 97145520138758844, 2054507019515346789, 45484006970415223287, 1052036480881734378541]

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

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