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.

A331721 Number of nonequivalent n-column nonnegative integer matrices with column sums 4 and any number of nonzero rows up to permutation of rows and columns.

Table of values

n a(n)
0 1
1 5
2 66
3 1338
4 43686
5 2142277
6 149056260
7 13991691663
8 1705750869937
9 262268740077763
10 49694977078927305
11 11388565848749818055
12 3107918736854019004136
13 996840601151518793573156
14 371595543159269706775806375
15 159437222426663041455988930042
16 78072200940916732097886063687252

List of values

[1, 5, 66, 1338, 43686, 2142277, 149056260, 13991691663, 1705750869937, 262268740077763, 49694977078927305, 11388565848749818055, 3107918736854019004136, 996840601151518793573156, 371595543159269706775806375, 159437222426663041455988930042, 78072200940916732097886063687252]

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

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