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 A251263 #6 Jun 02 2025 10:19:37 %S A251263 57,313,1667,9109,49872,273607,1501739,8244503,45265163,248529844, %T A251263 1364574377,7492353561,41137689397,225871759293,1240178072856, %U A251263 6809359068477,37387672585765,205281890979411,1127126987808309 %N A251263 Number of (n+1)X(3+1) 0..1 arrays with no 2X2 subblock having x11-x00 less than x10-x01. %C A251263 Column 3 of A251268 %H A251263 R. H. Hardin, <a href="/A251263/b251263.txt">Table of n, a(n) for n = 1..210</a> %F A251263 Empirical: a(n) = 6*a(n-1) +6*a(n-2) -55*a(n-3) +21*a(n-4) +97*a(n-5) -48*a(n-6) -52*a(n-7) +25*a(n-8) +5*a(n-9) -2*a(n-10) %e A251263 Some solutions for n=4 %e A251263 ..1..1..1..1....1..1..1..1....0..1..1..1....0..0..1..1....0..0..0..1 %e A251263 ..0..0..1..1....0..0..1..1....0..0..1..1....0..0..0..0....1..1..1..1 %e A251263 ..0..0..0..0....0..1..1..1....0..0..1..1....0..1..1..1....1..1..1..1 %e A251263 ..0..1..1..1....0..0..1..1....0..0..0..0....0..1..1..1....0..1..1..1 %e A251263 ..0..0..0..0....1..1..1..1....0..1..1..1....1..0..0..0....1..0..0..0 %K A251263 nonn %O A251263 1,1 %A A251263 _R. H. Hardin_, Dec 01 2014