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 A235678 #6 Jul 23 2025 08:44:17 %S A235678 33544,4178316,510685176,62100488254,7541722428052,915571832243030, %T A235678 111141360154581108,13491148978500627866,1637644495947011565142, %U A235678 198787774684087795661506,24130123777752397380536568 %N A235678 Number of (n+1)X(7+1) 0..1 arrays with the difference between each 2X2 subblock maximum and minimum lexicographically nondecreasing columnwise and nonincreasing rowwise. %C A235678 Column 7 of A235679 %H A235678 R. H. Hardin, <a href="/A235678/b235678.txt">Table of n, a(n) for n = 1..210</a> %e A235678 Some solutions for n=1 %e A235678 ..1..0..1..0..0..1..1..0....0..0..0..1..1..1..0..0....1..0..1..1..0..1..1..0 %e A235678 ..0..0..0..0..1..0..1..1....1..1..0..1..0..1..1..1....1..0..0..0..0..0..0..0 %K A235678 nonn %O A235678 1,1 %A A235678 _R. H. Hardin_, Jan 13 2014