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 A228464 #23 Mar 17 2018 05:45:51 %S A228464 44,383,1821,6254,17487,42386,92430,185727,349558,623513,1063283, %T A228464 1745172,2771393,4276212,6433004,9462285,13640784,19311619,26895641, %U A228464 36904010,49952067,66774566,88242330,115380395,149387706,191658429,243804943 %N A228464 Number of arrays of maxima of three adjacent elements of some 0..n array of length 9. %C A228464 See A228461 for explanation of definition. %H A228464 R. H. Hardin, <a href="/A228464/b228464.txt">Table of n, a(n) for n = 1..210</a> %F A228464 Empirical: a(n) = (4/315)*n^7 + (1/5)*n^6 + (91/45)*n^5 + (63/8)*n^4 + (2557/180)*n^3 + (517/40)*n^2 + (2419/420)*n + 1 = (n+1) *(n+2) *(32*n^5 + 408*n^4 + 3808*n^3 + 7605*n^2 + 5367*n + 1260)/2520. %F A228464 Conjectures from _Colin Barker_, Mar 16 2018: (Start) %F A228464 G.f.: x*(44 + 31*x - 11*x^2 - 54*x^3 + 75*x^4 - 28*x^5 + 8*x^6 - x^7) / (1 - x)^8. %F A228464 a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>8. %F A228464 (End) %e A228464 Some solutions for n=4: %e A228464 3 0 3 4 4 3 3 4 3 4 2 3 2 0 3 2 %e A228464 3 0 2 4 4 0 0 2 1 3 4 3 0 0 4 0 %e A228464 0 0 2 4 0 2 0 2 4 4 4 3 4 0 4 2 %e A228464 0 0 1 3 1 3 1 2 4 4 4 3 4 4 4 2 %e A228464 0 0 3 1 1 3 2 2 4 4 0 1 4 4 0 2 %e A228464 1 0 3 0 4 4 3 2 4 4 0 1 0 4 3 2 %e A228464 1 3 4 3 4 4 3 1 0 2 1 2 0 3 3 0 %Y A228464 Row 7 of A228461. Cf. A217949. %K A228464 nonn %O A228464 1,1 %A A228464 _R. H. Hardin_, Aug 22 2013