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 A251095 #6 Jul 23 2025 13:03:43 %S A251095 129,1109,9597,82814,713769,6151051,53009570,456842112,3937123328, %T A251095 33930621210,292418287803,2520096887534,21718506027532, %U A251095 187172766061609,1613078004734497,13901705381759445,119806613163586853 %N A251095 Number of (n+1)X(3+1) 0..1 arrays with no 2X2 subblock having its minimum diagonal element less than its minimum antidiagonal element. %C A251095 Column 3 of A251100 %H A251095 R. H. Hardin, <a href="/A251095/b251095.txt">Table of n, a(n) for n = 1..210</a> %F A251095 Empirical: a(n) = 16*a(n-1) -90*a(n-2) +285*a(n-3) -577*a(n-4) +763*a(n-5) -652*a(n-6) +352*a(n-7) -112*a(n-8) +16*a(n-9) %e A251095 Some solutions for n=4 %e A251095 ..0..0..1..0....0..1..0..0....0..1..1..1....1..0..0..0....1..1..0..1 %e A251095 ..1..0..1..1....0..0..0..0....0..0..1..1....1..1..0..0....0..0..0..1 %e A251095 ..0..0..0..1....0..0..0..0....1..0..0..1....0..1..0..0....1..1..0..0 %e A251095 ..1..1..0..1....0..0..1..1....0..1..0..0....0..0..1..0....0..1..1..0 %e A251095 ..0..1..0..1....1..0..1..1....0..0..0..1....0..0..0..1....0..0..0..0 %K A251095 nonn %O A251095 1,1 %A A251095 _R. H. Hardin_, Nov 29 2014