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 A301948 #4 Mar 29 2018 12:43:48 %S A301948 3,52,680,9084,120815,1608681,21418808,285190208,3797277789, %T A301948 50560399640,673206912325,8963686254378,119350632636165, %U A301948 1589142359440249,21159279866124406,281733805537736001,3751258912615316186 %N A301948 Number of nX5 0..1 arrays with every element equal to 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero. %C A301948 Column 5 of A301951. %H A301948 R. H. Hardin, <a href="/A301948/b301948.txt">Table of n, a(n) for n = 1..210</a> %F A301948 Empirical: a(n) = 16*a(n-1) -29*a(n-2) -114*a(n-3) +324*a(n-4) +8*a(n-5) -709*a(n-6) +690*a(n-7) +158*a(n-8) -448*a(n-9) -34*a(n-10) +116*a(n-11) +27*a(n-12) -4*a(n-13) for n>15 %e A301948 Some solutions for n=5 %e A301948 ..0..0..1..1..1. .0..0..0..0..1. .0..0..1..1..0. .0..0..1..0..0 %e A301948 ..0..0..0..0..0. .0..1..0..1..1. .0..1..0..0..0. .0..1..0..1..0 %e A301948 ..0..0..1..1..1. .1..0..0..0..0. .1..1..1..0..0. .1..1..1..0..0 %e A301948 ..0..0..0..0..0. .0..0..1..1..1. .1..0..0..1..1. .0..0..0..1..1 %e A301948 ..0..0..0..0..0. .1..1..1..1..1. .1..1..1..1..1. .0..0..0..1..1 %Y A301948 Cf. A301951. %K A301948 nonn %O A301948 1,1 %A A301948 _R. H. Hardin_, Mar 29 2018