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 A208349 #7 Apr 22 2021 15:39:30 %S A208349 15,868,12625,230387,4773885,103672036,2280287753,50481169071, %T A208349 1122098238432,24983185355723,556622494082921,12405478452873059, %U A208349 276529980588607690,6164555722628477878,137428302821781111484 %N A208349 Number of n X 4 0..3 arrays with new values 0..3 introduced in row major order and no element equal to any knight-move neighbor (colorings ignoring permutations of colors). %C A208349 Column 4 of A208353. %H A208349 R. H. Hardin, <a href="/A208349/b208349.txt">Table of n, a(n) for n = 1..129</a> %e A208349 Some solutions for n=4 %e A208349 ..0..0..0..0....0..0..0..0....0..1..1..0....0..0..0..1....0..0..1..0 %e A208349 ..1..1..1..1....1..1..1..2....0..1..2..0....1..0..1..1....2..1..1..2 %e A208349 ..2..2..3..2....2..1..2..3....0..2..2..2....2..2..2..3....2..3..1..0 %e A208349 ..2..0..3..3....3..0..3..2....3..1..2..0....3..0..3..3....2..3..3..2 %Y A208349 Cf. A208353. %K A208349 nonn %O A208349 1,1 %A A208349 _R. H. Hardin_ Feb 25 2012