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.

A159717 Number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 3 local maxima.

Table of values

n a(n)
1 0
2 0
3 6
4 1192
5 61830
6 2150688
7 62178928
8 1629254640
9 40346856234
10 965510596600
11 22606163844396
12 521603874280248
13 11911230805813846
14 269907065756299440
15 6079103449024019880
16 136243494317831152480
17 3040751938796332410018
18 67621304208554979697224
19 1499043510801269678080708

List of values

[0, 0, 6, 1192, 61830, 2150688, 62178928, 1629254640, 40346856234, 965510596600, 22606163844396, 521603874280248, 11911230805813846, 269907065756299440, 6079103449024019880, 136243494317831152480, 3040751938796332410018, 67621304208554979697224, 1499043510801269678080708]

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

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