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.

A068313 Number of (0,1)-matrices with sum of entries equal to n and no zero rows or columns, with weakly decreasing row sums and column sums.

Table of values

n a(n)
1 1
2 4
3 15
4 82
5 457
6 3231
7 24055
8 209375
9 1955288
10 20455936
11 229830841
12 2828166755
13 37228913365
14 528635368980
15 7990596990430
16 128909374528433
17 2202090635802581
18 39837079499488151
19 759320365206705013
20 15234890522990662422
21 320634889654149218205
22 7068984425261215971205

List of values

[1, 4, 15, 82, 457, 3231, 24055, 209375, 1955288, 20455936, 229830841, 2828166755, 37228913365, 528635368980, 7990596990430, 128909374528433, 2202090635802581, 39837079499488151, 759320365206705013, 15234890522990662422, 320634889654149218205, 7068984425261215971205]

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

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