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 A224348 #6 Jul 23 2025 05:06:30 %S A224348 10,100,788,5880,45064,349280,2710892,21021916,163012744,1264202660, %T A224348 9804721360,76042111360,589756075600,4573942739248,35473931052816, %U A224348 275123688202096,2133765358334352,16548755248130912,128346493442546640 %N A224348 Number of nX3 0..2 arrays with diagonals and antidiagonals unimodal and rows nondecreasing. %C A224348 Column 3 of A224353 %H A224348 R. H. Hardin, <a href="/A224348/b224348.txt">Table of n, a(n) for n = 1..210</a> %F A224348 Empirical: a(n) = 10*a(n-1) -16*a(n-2) -24*a(n-3) +164*a(n-4) -516*a(n-5) +140*a(n-6) +956*a(n-7) -1500*a(n-8) +3180*a(n-9) +60*a(n-10) %e A224348 Some solutions for n=3 %e A224348 ..1..2..2....0..0..1....1..1..1....0..1..2....0..1..1....0..1..1....0..2..2 %e A224348 ..0..0..2....1..1..1....1..1..1....0..0..2....2..2..2....1..1..1....0..2..2 %e A224348 ..0..0..0....0..2..2....0..0..2....0..0..2....1..1..2....0..0..0....0..0..2 %K A224348 nonn %O A224348 1,1 %A A224348 _R. H. Hardin_ Apr 04 2013