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 A297687 #4 Jan 03 2018 09:33:27 %S A297687 128,2570,94891,1955750,59210634,1487819051,41030621948,1066508741933, %T A297687 28748828127508,759564088991329,20288126990340123,538493726660721622, %U A297687 14345913847238205189,381379710626740656598,10150876741291095683850 %N A297687 Number of 7Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 1 or 4 neighboring 1s. %C A297687 Row 7 of A297682. %H A297687 R. H. Hardin, <a href="/A297687/b297687.txt">Table of n, a(n) for n = 1..210</a> %e A297687 Some solutions for n=3 %e A297687 ..1..0..0. .1..0..1. .0..1..1. .1..0..0. .1..0..0. .1..0..0. .1..0..1 %e A297687 ..0..1..0. .1..0..1. .0..0..0. .1..0..0. .0..0..1. .1..0..0. .1..0..0 %e A297687 ..0..0..0. .0..0..0. .0..0..1. .1..1..1. .1..1..1. .0..0..0. .0..0..0 %e A297687 ..0..0..1. .0..0..1. .0..0..1. .0..0..1. .0..0..1. .1..0..0. .0..0..0 %e A297687 ..1..0..0. .0..0..0. .0..1..1. .0..0..0. .1..0..0. .1..0..0. .0..0..0 %e A297687 ..1..0..1. .0..0..0. .1..0..1. .1..0..1. .0..0..1. .0..0..0. .0..0..1 %e A297687 ..0..0..0. .1..0..0. .1..0..0. .1..0..1. .0..0..1. .0..0..1. .0..0..0 %Y A297687 Cf. A297682. %K A297687 nonn %O A297687 1,1 %A A297687 _R. H. Hardin_, Jan 03 2018