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 A214239 #9 Mar 09 2018 10:21:19 %S A214239 1,1,4,11,41,162,715,3424,17686,97493,567986,3462537,21880951, %T A214239 142148644,942800317,6349172750,43233294236,296737912815, %U A214239 2048310985708,14196341292463,98674810415941,687263739609206,4793697038780159 %N A214239 Number of 0..7 colorings of a 1 X (n+1) array circular in the n+1 direction with new values 0..7 introduced in row major order. %C A214239 Row 1 of A214238. %H A214239 R. H. Hardin, <a href="/A214239/b214239.txt">Table of n, a(n) for n = 1..210</a> %F A214239 Empirical: a(n) = 21*a(n-1) - 168*a(n-2) + 630*a(n-3) - 1029*a(n-4) + 189*a(n-5) + 1198*a(n-6) - 840*a(n-7). %F A214239 Empirical g.f.: x*(1 - 20*x + 151*x^2 - 535*x^3 + 881*x^4 - 531*x^5) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)*(1 - 5*x)*(1 - 7*x)).- _Colin Barker_, Mar 09 2018 %e A214239 Some solutions for n=4: %e A214239 ..0..1..2..1..2.....0..1..0..2..1.....0..1..0..1..2.....0..1..2..3..1 %Y A214239 Cf. A214238. %K A214239 nonn %O A214239 1,3 %A A214239 _R. H. Hardin_, Jul 08 2012