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 A267473 #7 Feb 05 2018 09:36:22 %S A267473 21,160,712,2285,5921,13216,26440,48657,83845,137016,214336,323245, %T A267473 472577,672680,935536,1274881,1706325,2247472,2918040,3739981,4737601, %U A267473 5937680,7369592,9065425,11060101,13391496,16100560,19231437,22831585 %N A267473 Number of length-5 0..n arrays with no following elements larger than the first repeated value. %C A267473 Row 5 of A267471. %H A267473 R. H. Hardin, <a href="/A267473/b267473.txt">Table of n, a(n) for n = 1..210</a> %F A267473 Empirical: a(n) = n^5 + (37/12)*n^4 + (11/2)*n^3 + (77/12)*n^2 + 4*n + 1. %F A267473 Conjectures from _Colin Barker_, Feb 05 2018: (Start) %F A267473 G.f.: x*(21 + 34*x + 67*x^2 - 7*x^3 + 6*x^4 - x^5) / (1 - x)^6. %F A267473 a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6. %F A267473 (End) %e A267473 Some solutions for n=7: %e A267473 ..7....1....4....4....7....0....0....7....1....2....4....7....5....6....3....4 %e A267473 ..4....0....6....3....7....6....1....2....5....4....4....1....6....1....7....6 %e A267473 ..4....1....7....1....7....3....7....4....1....5....2....4....1....4....7....3 %e A267473 ..0....3....4....7....1....2....0....1....2....2....1....7....3....7....3....5 %e A267473 ..2....6....4....5....5....7....3....1....4....5....4....2....7....7....5....5 %Y A267473 Cf. A267471. %K A267473 nonn %O A267473 1,1 %A A267473 _R. H. Hardin_, Jan 15 2016