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.

A213691 Half the number of (n+1)X(n+1) symmetric 0..2 arrays with no 2X2 subblock summing to 4.

Table of values

n a(n)
1 11
2 192
3 7827
4 750261
5 168382284
6 88681187619
7 109492322533385
8 317058871268862262
9 2152886481426876004067
10 34281579489759899253123057
11 1280103594445094955653155909620
12 112093309434087933528612875492895053

List of values

[11, 192, 7827, 750261, 168382284, 88681187619, 109492322533385, 317058871268862262, 2152886481426876004067, 34281579489759899253123057, 1280103594445094955653155909620, 112093309434087933528612875492895053]

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

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