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 A223737 #6 Jul 23 2025 04:26:25 %S A223737 22,484,5600,42090,237088,1082738,4207089,14362171,44066468,123591226, %T A223737 321014080,780210492,1789329904,3899021174,8119048135,16234703963, %U A223737 31301451138,58398476624,105750499888,186363500950,320365509352 %N A223737 Number of nX3 0..2 arrays with rows, columns, diagonals and antidiagonals unimodal. %C A223737 Column 3 of A223742 %H A223737 R. H. Hardin, <a href="/A223737/b223737.txt">Table of n, a(n) for n = 1..210</a> %F A223737 Empirical: a(n) = (5051/239500800)*n^12 + (9539/39916800)*n^11 + (75941/21772800)*n^10 + (79/3840)*n^9 + (160763/1036800)*n^8 + (647089/1209600)*n^7 + (42743903/21772800)*n^6 + (1895941/725760)*n^5 + (37871509/5443200)*n^4 + (109751/43200)*n^3 + (125047/14850)*n^2 - (14101/1155)*n + 11 %e A223737 Some solutions for n=3 %e A223737 ..1..0..0....2..1..1....1..0..0....2..2..0....0..2..0....0..1..2....1..1..0 %e A223737 ..1..0..0....2..2..0....0..1..1....0..2..2....0..2..2....0..1..0....0..0..0 %e A223737 ..1..1..0....2..0..0....0..0..0....0..0..0....2..1..0....0..0..0....0..0..0 %K A223737 nonn %O A223737 1,1 %A A223737 _R. H. Hardin_ Mar 26 2013