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 A224155 #6 Jul 23 2025 05:01:04 %S A224155 16,101,373,1156,3469,10562,32910,105020,342575,1136503,3815322, %T A224155 12904448,43836891,149266926,508857756,1735637682,5921189882, %U A224155 20201365165,68920464104,235127759007,802136163910,2736424196762,9334965911219 %N A224155 Number of nX5 0..1 arrays with diagonals and rows unimodal and antidiagonals nondecreasing. %C A224155 Column 5 of A224158 %H A224155 R. H. Hardin, <a href="/A224155/b224155.txt">Table of n, a(n) for n = 1..210</a> %F A224155 Empirical: a(n) = 6*a(n-1) -9*a(n-2) -a(n-3) +a(n-4) +23*a(n-5) -38*a(n-6) +42*a(n-7) -41*a(n-8) +89*a(n-9) -67*a(n-10) -9*a(n-11) +5*a(n-12) -32*a(n-13) -50*a(n-14) -12*a(n-15) -58*a(n-16) -28*a(n-17) +12*a(n-18) +4*a(n-20) for n>22 %e A224155 Some solutions for n=3 %e A224155 ..1..1..0..0..0....1..0..0..0..0....1..0..0..0..0....0..1..0..0..0 %e A224155 ..1..1..1..0..0....0..0..0..0..0....0..1..0..0..0....1..1..1..0..0 %e A224155 ..1..1..1..1..1....0..0..0..1..0....1..0..0..0..0....1..1..0..0..0 %K A224155 nonn %O A224155 1,1 %A A224155 _R. H. Hardin_ Mar 31 2013