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 A269148 #4 Feb 20 2016 07:16:41 %S A269148 108,6224,220968,7002040,208984848,6004186984,167970539096, %T A269148 4607603633440,124496158984840,3323815506994632,87881068225023056, %U A269148 2304923699010954504,60044569367490800584,1555171706058316642096,40078683916858034569112 %N A269148 Number of nX4 0..3 arrays with some element plus some horizontally, antidiagonally or vertically adjacent neighbor totalling three exactly once. %C A269148 Column 4 of A269152. %H A269148 R. H. Hardin, <a href="/A269148/b269148.txt">Table of n, a(n) for n = 1..210</a> %F A269148 Empirical: a(n) = 58*a(n-1) -1093*a(n-2) +7680*a(n-3) -27078*a(n-4) +58958*a(n-5) -88914*a(n-6) +82212*a(n-7) -35159*a(n-8) -20796*a(n-9) +39556*a(n-10) -11364*a(n-11) -13593*a(n-12) +9618*a(n-13) +429*a(n-14) -2060*a(n-15) +434*a(n-16) +166*a(n-17) -92*a(n-18) +16*a(n-19) -a(n-20) for n>22 %e A269148 Some solutions for n=2 %e A269148 ..2..2..0..2. .0..2..3..3. .3..3..2..2. .3..3..0..1. .0..2..3..2 %e A269148 ..2..2..3..3. .0..3..2..3. .1..0..0..0. .3..1..1..0. .3..3..3..3 %Y A269148 Cf. A269152. %K A269148 nonn %O A269148 1,1 %A A269148 _R. H. Hardin_, Feb 20 2016