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 A235445 #7 Jul 23 2025 08:34:24 %S A235445 742,15936,335898,7017768,146213244,3043145826,63315473350, %T A235445 1317184566572,27401048899854,570010121664030,11857587445735140, %U A235445 246666181271526484,5131244813184060086,106742118037538403444,2220490316595946662760 %N A235445 Number of (n+1)X(4+1) 0..1 arrays with the difference between each 2X2 subblock maximum and minimum lexicographically nondecreasing rowwise and columnwise. %C A235445 Column 4 of A235449 %H A235445 R. H. Hardin, <a href="/A235445/b235445.txt">Table of n, a(n) for n = 1..210</a> %H A235445 R. H. Hardin, <a href="/A235445/a235445.txt">Empirical recurrence of order 53</a> %F A235445 Empirical recurrence of order 53 (see link above) %e A235445 Some solutions for n=2 %e A235445 ..1..1..1..0..1....1..0..1..1..0....1..1..0..0..0....0..1..0..0..0 %e A235445 ..1..0..1..1..1....0..0..1..0..0....1..0..1..1..1....1..1..1..1..0 %e A235445 ..1..0..0..1..0....0..1..0..1..1....0..0..1..0..0....0..0..0..1..1 %K A235445 nonn %O A235445 1,1 %A A235445 _R. H. Hardin_, Jan 10 2014