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.

A225978 Number of nX4 binary arrays whose sum with another nX4 binary array containing no more than two 1s has rows and columns in lexicographically nondecreasing order.

Table of values

n a(n)
1 15
2 138
3 1178
4 9113
5 61808
6 361361
7 1825607
8 8065278
9 31631401
10 111785599
11 360788468
12 1075829429
13 2993017696
14 7832960008
15 19417916324
16 45865067963
17 103734768130
18 225619306783
19 473616394498
20 962612525277
21 1899542726132

List of values

[15, 138, 1178, 9113, 61808, 361361, 1825607, 8065278, 31631401, 111785599, 360788468, 1075829429, 2993017696, 7832960008, 19417916324, 45865067963, 103734768130, 225619306783, 473616394498, 962612525277, 1899542726132]

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

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