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 A224286 #6 Jul 23 2025 05:05:01 %S A224286 16384,16000000,537465766,6172817040,45275725025,274116529912, %T A224286 1597855917875,9622753439382,59980603070388,376494813177039, %U A224286 2313407919278369,13634051825496929,76116429236458083,400003671053134168 %N A224286 Number of 7Xn 0..3 arrays with diagonals and rows unimodal and antidiagonals nondecreasing. %C A224286 Row 7 of A224281 %H A224286 R. H. Hardin, <a href="/A224286/b224286.txt">Table of n, a(n) for n = 1..46</a> %e A224286 Some solutions for n=3 %e A224286 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A224286 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A224286 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..1....0..0..0 %e A224286 ..0..2..0....2..2..2....3..0..0....0..0..0....0..0..0....3..2..2....3..2..0 %e A224286 ..2..2..2....3..2..2....3..2..0....1..2..0....0..1..0....2..2..0....3..0..0 %e A224286 ..2..2..2....3..2..2....3..2..2....2..1..0....1..0..0....2..3..2....3..1..0 %e A224286 ..3..3..2....2..2..2....3..2..1....1..2..1....3..3..1....3..3..0....2..3..0 %K A224286 nonn %O A224286 1,1 %A A224286 _R. H. Hardin_ Apr 02 2013