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.

A331396 Number of nonnegative integer matrices with 2 distinct columns and any number of nonzero rows with column sums n and columns in decreasing lexicographic order.

Table of values

n a(n)
1 1
2 12
3 124
4 1280
5 13456
6 143808
7 1556416
8 17006592
9 187207936
10 2072947712
11 23063919616
12 257634271232
13 2887544049664
14 32456082440192
15 365710391885824
16 4129672996585472
17 46721752249729024
18 529486122704437248
19 6009576477811277824
20 68299997524116111360

List of values

[1, 12, 124, 1280, 13456, 143808, 1556416, 17006592, 187207936, 2072947712, 23063919616, 257634271232, 2887544049664, 32456082440192, 365710391885824, 4129672996585472, 46721752249729024, 529486122704437248, 6009576477811277824, 68299997524116111360]

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

Content is available under The OEIS End-User License Agreement.