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 A223818 #5 Sep 03 2022 20:30:04 %S A223818 15,867,43941,1941904,76453838,2740448352,91020540767,2837847226191, %T A223818 83919692408722,2372632276864454,64552746518391559, %U A223818 1698928155067259979,43440043738459660061,1082941619670703392975 %N A223818 Number of 4 X n 0..2 arrays with row sums nondecreasing and column sums unimodal. %C A223818 Row 4 of A223815. %e A223818 Some solutions for n=3 %e A223818 ..1..1..0....0..1..0....0..0..1....1..2..0....2..1..0....0..0..1....1..1..1 %e A223818 ..0..2..0....0..2..0....0..2..1....1..0..2....2..0..1....1..0..0....0..2..2 %e A223818 ..0..2..1....1..2..2....2..1..0....1..1..1....1..2..0....1..1..1....1..2..2 %e A223818 ..1..2..1....2..2..2....2..1..2....1..2..0....2..0..1....1..2..2....2..2..1 %Y A223818 Cf. A223815. %K A223818 nonn %O A223818 1,1 %A A223818 _R. H. Hardin_, Mar 27 2013