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.

A331397 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)
0 1
1 2
2 14
3 128
4 1288
5 13472
6 143840
7 1556480
8 17006720
9 187208192
10 2072948224
11 23063920640
12 257634273280
13 2887544053760
14 32456082448384
15 365710391902208
16 4129672996618240
17 46721752249794560
18 529486122704568320
19 6009576477811539968
20 68299997524116635648

List of values

[1, 2, 14, 128, 1288, 13472, 143840, 1556480, 17006720, 187208192, 2072948224, 23063920640, 257634273280, 2887544053760, 32456082448384, 365710391902208, 4129672996618240, 46721752249794560, 529486122704568320, 6009576477811539968, 68299997524116635648]

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

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