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 A214108 #8 Jul 22 2025 23:08:11 %S A214108 10,670,44900,3008980,201647240,13513419640,905603817680, %T A214108 60689173906000,4067093973641120,272556904729800160, %U A214108 18265441319366096960,1224061254004727782720,82030646145243326825600 %N A214108 Number of 0..3 colorings on an nX5 array circular in the 5 direction with new values 0..3 introduced in row major order. %C A214108 Column 4 of A214112 %H A214108 R. H. Hardin, <a href="/A214108/b214108.txt">Table of n, a(n) for n = 1..210</a> %F A214108 Empirical: a(n) = 68*a(n-1) -66*a(n-2). %F A214108 Empirical: G.f. -10*x*(-1+x) / ( 1-68*x+66*x^2 ). - _R. J. Mathar_, Jul 04 2012 %e A214108 Some solutions for n=4 %e A214108 ..0..1..2..3..1....0..1..0..1..2....0..1..0..1..2....0..1..0..2..3 %e A214108 ..3..2..0..1..2....1..0..1..0..3....2..3..1..2..0....1..2..1..3..0 %e A214108 ..1..3..1..2..0....2..1..3..2..1....1..0..2..0..2....3..1..3..1..2 %e A214108 ..0..1..0..3..1....3..0..1..0..2....2..1..3..1..0....0..3..1..2..1 %K A214108 nonn %O A214108 1,1 %A A214108 _R. H. Hardin_ Jul 04 2012