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.

A139046 Half the number of symmetric n X n binary matrices with the center of gravity of the 1s at the center.

Table of values

n a(n)
1 1
2 2
3 12
4 52
5 1992
6 43472
7 8084672
8 785972800
9 632010796352
10 260819509251776
11 879345967412550400
12 1508148706710022883840
13 20993821611583601278837888
14 147923394778079541856196475392
15 8426633557858801012990635249817088

List of values

[1, 2, 12, 52, 1992, 43472, 8084672, 785972800, 632010796352, 260819509251776, 879345967412550400, 1508148706710022883840, 20993821611583601278837888, 147923394778079541856196475392, 8426633557858801012990635249817088]

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

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