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 A223059 #6 Jul 23 2025 03:26:42 %S A223059 51,19360,9383963,4606719559,2266567594841,1115636153544055, %T A223059 549172612438350029,270334270159303305523,133074373792931796543737, %U A223059 65507037468442048450168351,32246421320132829050759287877 %N A223059 Number of nX5 0..3 arrays with all horizontally or vertically connected equal values in a straight line, and new values 0..3 introduced in row major order. %C A223059 Column 5 of A223062 %H A223059 R. H. Hardin, <a href="/A223059/b223059.txt">Table of n, a(n) for n = 1..210</a> %e A223059 Some solutions for n=3 %e A223059 ..0..0..0..0..0....0..0..0..1..0....0..0..0..0..1....0..0..0..1..0 %e A223059 ..1..2..1..1..1....2..2..3..0..2....2..3..2..1..0....2..2..2..0..1 %e A223059 ..2..3..2..3..3....1..0..3..2..0....0..0..1..3..3....0..1..1..2..1 %K A223059 nonn %O A223059 1,1 %A A223059 _R. H. Hardin_ Mar 13 2013