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.

A221626 Number of 4Xn arrays with each row a permutation of 1..n having at least as many downsteps as the preceding row.

Table of values

n a(n)
1 1
2 5
3 453
4 85035
5 51149685
6 57614883627
7 130516916069715
8 492362067027383802
9 3063154239917651379537
10 28932140956374841410316707
11 405028623674958829496315433651
12 8040080740216333451541433497055002

List of values

[1, 5, 453, 85035, 51149685, 57614883627, 130516916069715, 492362067027383802, 3063154239917651379537, 28932140956374841410316707, 405028623674958829496315433651, 8040080740216333451541433497055002]

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

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