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.

A151642 Number of permutations of 4 indistinguishable copies of 1..n with exactly 4 adjacent element pairs in decreasing order.

Table of values

n a(n)
1 0
2 1
3 13840
4 4961755
5 733059110
6 75073622025
7 6438673851876
8 503519287150295
9 37463016470769170
10 2712124797724710645
11 193396524783642727120
12 13675857973300537321251
13 962624331855762939745950
14 67586399804656292725004385
15 4738724382451462432861849980

List of values

[0, 1, 13840, 4961755, 733059110, 75073622025, 6438673851876, 503519287150295, 37463016470769170, 2712124797724710645, 193396524783642727120, 13675857973300537321251, 962624331855762939745950, 67586399804656292725004385, 4738724382451462432861849980]

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

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