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 A235448 #6 Jul 23 2025 08:34:37 %S A235448 33544,4219322,519099694,63315473350,7699719982722,935263088301396, %T A235448 113555975474406500,13785363846787350466,1673407961412976159218, %U A235448 203131147623014349473962,24657443308255446422188572 %N A235448 Number of (n+1)X(7+1) 0..1 arrays with the difference between each 2X2 subblock maximum and minimum lexicographically nondecreasing rowwise and columnwise. %C A235448 Column 7 of A235449 %H A235448 R. H. Hardin, <a href="/A235448/b235448.txt">Table of n, a(n) for n = 1..77</a> %e A235448 Some solutions for n=1 %e A235448 ..0..1..0..1..1..0..0..0....1..1..0..1..1..1..1..1....1..1..0..1..0..0..1..0 %e A235448 ..1..1..1..0..1..1..0..1....1..0..1..0..0..0..0..0....1..0..0..0..1..0..0..0 %K A235448 nonn %O A235448 1,1 %A A235448 _R. H. Hardin_, Jan 10 2014