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 A214168 #6 Jun 18 2022 17:25:27 %S A214168 4,18,337,5994,121778,2518082,52655411,1103993538,23172461572, %T A214168 486537381066,10216717221605,214546979103002,4505458523356886, %U A214168 94614430060611570,1986901652087170519,41724924973226947986 %N A214168 Number of 0..5 colorings of a 2 X (n+1) array circular in the n+1 direction with new values 0..5 introduced in row major order. %C A214168 Row 2 of A214166. %H A214168 R. H. Hardin, <a href="/A214168/b214168.txt">Table of n, a(n) for n = 1..210</a> %F A214168 Empirical: a(n) = 21*a(n-1) +49*a(n-2) -959*a(n-3) -1869*a(n-4) +7679*a(n-5) +15051*a(n-6) -6741*a(n-7) -13230*a(n-8). %e A214168 Some solutions for n=4 %e A214168 ..0..1..0..2..1....0..1..0..2..1....0..1..0..1..2....0..1..0..1..2 %e A214168 ..1..2..1..0..2....2..3..1..4..5....1..0..1..0..3....2..3..1..0..3 %Y A214168 Cf. A214166. %K A214168 nonn %O A214168 1,1 %A A214168 _R. H. Hardin_, Jul 05 2012