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 A223827 #6 Mar 01 2023 13:38:43 %S A223827 46,2116,51136,738482,7291180,54035194,320423509,1590193515, %T A223827 6823643014,25942390362,89032405314,279892497568,815488308996, %U A223827 2223043463584,5714420877205,13941660959025,32460302492138,72461547637300 %N A223827 Number of n X 4 0..2 arrays with rows and columns unimodal. %C A223827 Column 4 of A223831. %H A223827 R. H. Hardin, <a href="/A223827/b223827.txt">Table of n, a(n) for n = 1..210</a> %F A223827 Empirical: a(n) = (456419/5230697472000)*n^16 + (35741/12108096000)*n^15 + (154711/2874009600)*n^14 + (1309129/2075673600)*n^13 + (149137159/28740096000)*n^12 + (924691/29568000)*n^11 + (261112321/1828915200)*n^10 + (17095201/33868800)*n^9 + (7372850867/5225472000)*n^8 + (227410163/72576000)*n^7 + (8054484973/1437004800)*n^6 + (6610049/831600)*n^5 + (112396487393/12108096000)*n^4 + (4125505841/504504000)*n^3 + (671183/110880)*n^2 + (27067/10010)*n + 1. %e A223827 Some solutions for n=3 %e A223827 ..2..2..1..0....0..0..2..2....2..2..0..0....0..0..2..2....0..0..0..0 %e A223827 ..2..2..1..1....2..2..2..1....2..2..2..2....0..2..2..2....1..1..0..0 %e A223827 ..0..2..2..2....0..0..2..0....0..1..2..2....0..0..1..2....0..0..0..1 %Y A223827 Cf. A223831. %K A223827 nonn %O A223827 1,1 %A A223827 _R. H. Hardin_, Mar 27 2013