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 A223616 #8 Aug 21 2018 10:16:33 %S A223616 11,121,876,4466,17594,57238,160883,403159,921181,1951247,3879910, %T A223616 7312800,13164932,22776596,38059285,61676477,97264447,149698645, %U A223616 225411536,332768158,482506014,688246274,967083623,1340262451,1833947441 %N A223616 Number of n X 4 0..1 arrays with rows and columns unimodal. %C A223616 Column 4 of A223620. %H A223616 R. H. Hardin, <a href="/A223616/b223616.txt">Table of n, a(n) for n = 1..210</a> %F A223616 Empirical: a(n) = (1/112)*n^8 + (79/1260)*n^7 + (59/180)*n^6 + (299/360)*n^5 + (259/144)*n^4 + (821/360)*n^3 + (7219/2520)*n^2 + (767/420)*n + 1. %F A223616 Conjectures from _Colin Barker_, Aug 21 2018: (Start) %F A223616 G.f.: x*(11 + 22*x + 183*x^2 + 14*x^3 + 158*x^4 - 56*x^5 + 35*x^6 - 8*x^7 + x^8) / (1 - x)^9. %F A223616 a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n>9. %F A223616 (End) %e A223616 Some solutions for n=4: %e A223616 ..0..0..1..0....0..0..1..1....1..0..0..0....1..0..0..0....0..0..1..0 %e A223616 ..1..1..1..1....0..1..1..1....0..0..0..0....1..1..1..0....0..0..1..1 %e A223616 ..1..1..1..0....0..0..1..0....0..0..1..0....0..0..0..0....0..1..1..1 %e A223616 ..0..0..1..0....0..0..1..0....0..0..0..1....0..0..0..0....0..1..1..1 %Y A223616 Cf. A223620. %K A223616 nonn %O A223616 1,1 %A A223616 _R. H. Hardin_, Mar 24 2013