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.

A331706 Number of nonnegative integer matrices with 2 distinct columns and any number of distinct nonzero rows with column sums n and columns in decreasing lexicographic order.

Table of values

n a(n)
0 0
1 1
2 6
3 42
4 268
5 1239
6 7278
7 40828
8 201084
9 1044693
10 5171998
11 24532674
12 116470596
13 546141979
14 2505755010
15 11318525016
16 50046272884
17 219637249269
18 944072863998
19 4029243437158
20 16977344149608
21 70370874102975
22 289702060529770
23 1177283903977008
24 4740700176809748

List of values

[0, 1, 6, 42, 268, 1239, 7278, 40828, 201084, 1044693, 5171998, 24532674, 116470596, 546141979, 2505755010, 11318525016, 50046272884, 219637249269, 944072863998, 4029243437158, 16977344149608, 70370874102975, 289702060529770, 1177283903977008, 4740700176809748]

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

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