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 A242235 #20 Jan 05 2019 07:54:21 %S A242235 15,35,71,139,271,531,1047,2059,4047,7955,15639,30747,60447,118835, %T A242235 233623,459291,902943,1775139,3489831,6860827,13488031,26516771, %U A242235 52130599,102486059,201482287,396103747,778719463,1530922155,3009713711 %N A242235 Number of length n+4+1 0..4 arrays with every value 0..4 appearing at least once in every consecutive 4+2 elements, and new values 0..4 introduced in order. %H A242235 R. H. Hardin, <a href="/A242235/b242235.txt">Table of n, a(n) for n = 1..210</a> %F A242235 Empirical: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4) + a(n-5). %F A242235 Conjecture: a(n) = 16*A145113(n-1) + A004767(n-2), n > 1. - _R. J. Mathar_, Aug 16 2017 %F A242235 Empirical g.f.: x*(15 + 20*x + 21*x^2 + 18*x^3 + 11*x^4) / (1 - x - x^2 - x^3 - x^4 - x^5). - _Colin Barker_, Oct 31 2018 %e A242235 Some solutions for n=5: %e A242235 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 %e A242235 0 1 1 1 1 1 1 1 1 0 1 1 0 1 1 1 %e A242235 1 2 2 2 2 0 2 0 0 1 2 2 1 2 2 2 %e A242235 2 3 0 1 3 2 3 2 2 2 2 3 2 0 3 0 %e A242235 3 2 3 3 4 3 0 3 3 3 3 4 3 3 0 3 %e A242235 4 4 4 4 1 4 4 4 4 4 4 1 4 4 4 4 %e A242235 1 0 1 0 0 1 1 0 0 2 0 0 0 0 1 2 %e A242235 0 1 2 3 2 2 2 1 1 0 1 2 1 1 2 1 %e A242235 4 3 3 2 2 0 3 1 3 1 2 4 2 2 3 0 %e A242235 2 0 0 1 3 1 4 2 2 0 1 3 2 2 0 1 %Y A242235 Cf. A004767, A145113, A242239. %Y A242235 Column 4 of A242239. %K A242235 nonn %O A242235 1,1 %A A242235 _R. H. Hardin_, May 08 2014