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.

A221027 Sum of neighbor maps: log base 2 of the number of nX7 binary arrays indicating the locations of corresponding elements equal to the sum mod 2 of their horizontal, vertical and antidiagonal neighbors in a random 0..1 nX7 array.

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%I A221027 #5 Jul 23 2025 01:38:10
%S A221027 7,13,19,27,35,42,45,53,62,69,72,83,90,95,101,112,119,125,131,139,147,
%T A221027 154,154,168,175,181,187,195,203,210,213
%N A221027 Sum of neighbor maps: log base 2 of the number of nX7 binary arrays indicating the locations of corresponding elements equal to the sum mod 2 of their horizontal, vertical and antidiagonal neighbors in a random 0..1 nX7 array.
%C A221027 Column 7 of A221028
%e A221027 Some solutions for n=3
%e A221027 ..0..0..0..1..1..0..1....0..0..0..1..0..1..1....0..1..1..0..1..0..0
%e A221027 ..0..1..1..0..0..0..0....0..0..1..1..1..0..0....0..1..1..1..1..0..0
%e A221027 ..0..0..0..1..1..0..0....1..0..1..0..0..1..0....0..0..0..0..0..1..1
%K A221027 nonn
%O A221027 1,1
%A A221027 _R. H. Hardin_ Dec 29 2012