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.
%I A278202 #6 Apr 21 2020 12:50:46 %S A278202 0,3,97,8242,3295771,5306819216,33056811286568,812312404546266967, %T A278202 78877646007318566942149,30229204386668969418436705255, %U A278202 45720403850059908972915757270717926 %N A278202 Number of n X n 0..1 arrays with every element both equal and not equal to some elements at offset (-1,-1), (-1,0), (-1,1), (0,-1), (0,1), (1,-1), (1,0) or (1,1), with upper left element zero. %C A278202 Diagonal of A278208. %e A278202 Some solutions for n=4 %e A278202 ..0..1..1..1. .0..1..0..0. .0..0..1..1. .0..1..0..0. .0..1..0..1 %e A278202 ..0..1..0..0. .1..0..1..1. .0..1..0..0. .0..1..1..1. .0..1..1..0 %e A278202 ..1..0..0..0. .1..1..0..1. .1..1..1..1. .0..1..0..1. .1..1..1..1 %e A278202 ..1..1..1..0. .0..0..0..0. .1..0..0..0. .0..1..1..0. .1..0..0..1 %Y A278202 Cf. A278208. %K A278202 nonn %O A278202 1,2 %A A278202 _R. H. Hardin_, Nov 15 2016