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.

A221620 Number of n X 5 arrays with each row a permutation of 1..5 having at least as many downsteps as the preceding row.

Table of values

n a(n)
1 120
2 10055
3 738150
4 51149685
5 3451956516
6 230141263315
7 15258126049410
8 1009051056050225
9 66655625407012320
10 4400938611593606031
11 290509268912775739710
12 19174945298440265379565
13 1265583745617128902739100

List of values

[120, 10055, 738150, 51149685, 3451956516, 230141263315, 15258126049410, 1009051056050225, 66655625407012320, 4400938611593606031, 290509268912775739710, 19174945298440265379565, 1265583745617128902739100]

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

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