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 A224376 #8 Jul 07 2023 19:14:28 %S A224376 81,1944,15540,77793,311367,1092281,3518302,10643789,30548895, %T A224376 83538706,218139823,544930741,1304961768,3002671615,6654904188, %U A224376 14242413828,29504608642,59301307852,115889490174,220645337145,410024971049 %N A224376 Number of 4 X n 0..2 arrays with rows unimodal and antidiagonals nondecreasing. %H A224376 R. H. Hardin, <a href="/A224376/b224376.txt">Table of n, a(n) for n = 1..210</a> %F A224376 Empirical: a(n) = (1/106748928000)*n^16 + (1/1482624000)*n^15 + (7/266872320)*n^14 + (127/197683200)*n^13 + (315179/28740096000)*n^12 + (24499/177408000)*n^11 + (89507/65318400)*n^10 + (112109/9676800)*n^9 + (68633371/746496000)*n^8 + (11395841/16128000)*n^7 + (6723664007/1437004800)*n^6 + (295741651/13305600)*n^5 + (262119224347/5189184000)*n^4 - (16331232329/1297296000)*n^3 + (12600631/343200)*n^2 + (38790413/360360)*n - 166 for n>2. %e A224376 Some solutions for n=3 %e A224376 ..0..0..0....2..0..0....2..0..0....0..0..0....1..2..1....1..1..1....0..1..2 %e A224376 ..1..1..2....2..0..0....0..0..0....1..0..0....2..2..1....1..2..2....1..2..0 %e A224376 ..1..2..1....0..0..0....0..1..1....2..1..1....2..1..1....2..2..2....2..2..0 %e A224376 ..2..2..1....2..1..0....2..2..1....2..2..2....2..1..1....2..2..0....2..2..2 %Y A224376 Row 4 of A224374. %K A224376 nonn %O A224376 1,1 %A A224376 _R. H. Hardin_, Apr 05 2013