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 A224121 #7 Jul 23 2025 04:59:54 %S A224121 50,1747,47059,1070499,21632718,400993828,6962188526,114852977638, %T A224121 1818933416948,27867476494858,415428832366407,6052984236034862, %U A224121 86509041863415952,1216196228905636823,16857689384122403297 %N A224121 Number of nX3 0..3 arrays with row sums nondecreasing and column sums unimodal. %C A224121 Column 3 of A224123 %H A224121 R. H. Hardin, <a href="/A224121/b224121.txt">Table of n, a(n) for n = 1..22</a> %e A224121 Some solutions for n=3 %e A224121 ..1..1..0....1..1..2....2..0..2....0..0..0....2..1..2....1..1..0....1..1..2 %e A224121 ..0..1..1....3..3..2....3..3..1....2..3..2....2..3..0....2..2..0....3..3..0 %e A224121 ..3..2..3....3..3..2....2..3..2....3..3..3....2..3..3....3..1..0....2..3..2 %K A224121 nonn %O A224121 1,1 %A A224121 _R. H. Hardin_ Mar 31 2013