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 A300774 #4 Mar 12 2018 11:27:45 %S A300774 0,19,102,735,10374,116954,1413931,17336190,210669938,2579232344, %T A300774 31507335039,385235115962,4709579663351,57576031578161, %U A300774 703919626655464,8605843851625144,105213106646598954,1286307937687623392 %N A300774 Number of nX6 0..1 arrays with every element equal to 2, 3, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. %C A300774 Column 6 of A300776. %H A300774 R. H. Hardin, <a href="/A300774/b300774.txt">Table of n, a(n) for n = 1..210</a> %e A300774 Some solutions for n=5 %e A300774 ..0..0..1..1..0..0. .0..0..1..1..0..0. .0..0..0..0..0..0. .0..0..1..1..0..0 %e A300774 ..0..1..1..1..0..0. .0..1..1..1..0..1. .0..0..1..1..1..0. .0..0..1..0..0..0 %e A300774 ..1..0..0..0..1..1. .0..0..0..0..1..1. .0..1..1..1..1..0. .0..1..1..1..1..0 %e A300774 ..1..0..0..1..1..0. .1..1..1..0..0..1. .1..1..1..1..1..0. .1..1..0..1..1..0 %e A300774 ..1..1..1..1..0..0. .1..1..1..0..1..1. .1..1..1..1..0..0. .1..0..0..0..0..0 %Y A300774 Cf. A300776. %K A300774 nonn %O A300774 1,2 %A A300774 _R. H. Hardin_, Mar 12 2018