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.

A033815 Number of standard permutations of [ a_1..a_n b_1..b_n ] (b_i is not immediately followed by a_i, for all i).

Table of values

n a(n)
0 1
1 1
2 14
3 426
4 24024
5 2170680
6 287250480
7 52370755920
8 12585067447680
9 3854801333416320
10 1465957162768492800
11 677696237345719468800
12 374281829360322587827200
13 243388909697235614324812800
14 184070135024053703140543027200
15 160192129141963141211280644352000

List of values

[1, 1, 14, 426, 24024, 2170680, 287250480, 52370755920, 12585067447680, 3854801333416320, 1465957162768492800, 677696237345719468800, 374281829360322587827200, 243388909697235614324812800, 184070135024053703140543027200, 160192129141963141211280644352000]

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

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