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 A254455 #6 Jul 23 2025 14:41:44 %S A254455 1511152,48345120,1621936236,48236381800,1361600709160,37859718002056, %T A254455 1041397026476012,28507415268662616,779944689953699120, %U A254455 21337775023347609896,583732130351416160872,15969189842148957483904 %N A254455 Number of (n+2)X(6+2) 0..1 arrays with every 3X3 subblock diagonal maximum minus antidiagonal median nondecreasing horizontally and vertically. %C A254455 Column 6 of A254457 %H A254455 R. H. Hardin, <a href="/A254455/b254455.txt">Table of n, a(n) for n = 1..210</a> %e A254455 Some solutions for n=1 %e A254455 ..0..0..0..0..1..0..1..0....0..0..0..0..1..0..0..0....0..0..0..0..0..1..1..1 %e A254455 ..1..1..0..0..0..1..1..1....0..0..0..0..1..0..1..0....1..1..1..0..0..1..1..1 %e A254455 ..1..0..0..0..0..0..0..0....1..1..0..0..0..0..1..1....1..1..0..1..0..1..1..1 %K A254455 nonn %O A254455 1,1 %A A254455 _R. H. Hardin_, Jan 30 2015