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 A297856 #4 Jan 07 2018 10:40:20 %S A297856 5,49,33,90,81,131,146,252,320,522,705,1188,1654,2554,4086,6240,9384, %T A297856 14677,22912,34760,54598,85044,131603,204203,317467,494005,767077, %U A297856 1194926,1861059,2894147,4502964,7013005,10913427,17000934,26479606 %N A297856 Number of nX6 0..1 arrays with every element equal to 1, 2 or 4 king-move adjacent elements, with upper left element zero. %C A297856 Column 6 of A297858. %H A297856 R. H. Hardin, <a href="/A297856/b297856.txt">Table of n, a(n) for n = 1..210</a> %e A297856 Some solutions for n=7 %e A297856 ..0..0..1..0..0..1. .0..1..0..1..0..0. .0..0..0..1..1..1. .0..0..1..0..1..0 %e A297856 ..1..0..1..1..1..1. .0..1..0..1..1..1. .0..1..0..1..0..1. .1..1..0..1..0..0 %e A297856 ..0..1..0..1..0..0. .1..1..1..0..1..0. .0..0..1..0..1..1. .1..0..1..0..1..1 %e A297856 ..1..1..0..1..0..1. .0..0..1..0..1..0. .1..1..0..1..0..0. .1..1..1..0..0..0 %e A297856 ..0..0..0..0..1..0. .1..1..1..0..1..0. .1..0..1..0..1..0. .0..0..0..0..1..1 %e A297856 ..1..0..1..1..0..1. .0..1..0..1..1..1. .1..1..0..1..0..0. .1..1..1..0..1..0 %e A297856 ..1..0..1..0..1..0. .0..1..0..1..0..0. .0..0..1..0..1..1. .0..0..0..1..0..1 %Y A297856 Cf. A297858. %K A297856 nonn %O A297856 1,1 %A A297856 _R. H. Hardin_, Jan 07 2018