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 A298885 #4 Jan 28 2018 08:45:44 %S A298885 3,23,23,73,123,243,444,897,1801,3462,6669,13291,25762,49483,97860, %T A298885 193033,376031,735990,1440269,2815283,5522803,10827092,21196028, %U A298885 41505035,81298779,159266998,311969014,611140770,1197086348,2345047342,4593936013 %N A298885 Number of nX5 0..1 arrays with every element equal to 1, 2, 4, 6 or 8 king-move adjacent elements, with upper left element zero. %C A298885 Column 5 of A298888. %H A298885 R. H. Hardin, <a href="/A298885/b298885.txt">Table of n, a(n) for n = 1..210</a> %e A298885 Some solutions for n=7 %e A298885 ..0..1..0..0..1. .0..0..0..1..0. .0..0..0..1..0. .0..1..1..0..1 %e A298885 ..0..1..1..1..0. .1..1..1..0..0. .1..1..1..1..0. .1..0..0..0..1 %e A298885 ..0..1..1..1..0. .0..0..0..0..0. .0..1..1..1..0. .1..0..0..0..1 %e A298885 ..1..1..1..1..1. .1..0..0..0..1. .0..1..1..1..1. .0..0..0..0..0 %e A298885 ..0..0..0..1..1. .1..0..0..0..1. .1..0..0..1..1. .1..1..1..0..0 %e A298885 ..1..1..1..1..0. .1..0..1..1..0. .0..0..1..1..0. .0..0..0..0..1 %e A298885 ..0..0..0..1..0. .0..0..1..0..1. .1..1..0..1..0. .1..1..1..0..1 %Y A298885 Cf. A298888. %K A298885 nonn %O A298885 1,1 %A A298885 _R. H. Hardin_, Jan 28 2018