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 A254171 #6 Jul 23 2025 14:29:50 %S A254171 76832,1014816,13514192,191190272,2589374656,34167243308,443654425392, %T A254171 5720473079212,73617021646416,947269263443756,12190444367623280, %U A254171 156900818355391996,2019616532033996096,25997546502044733452 %N A254171 Number of (4+2)X(n+2) 0..1 arrays with every 3X3 subblock diagonal maximum minus antidiagonal median nondecreasing horizontally, vertically and ne-to-sw antidiagonally. %C A254171 Row 4 of A254168 %H A254171 R. H. Hardin, <a href="/A254171/b254171.txt">Table of n, a(n) for n = 1..210</a> %e A254171 Some solutions for n=1 %e A254171 ..0..1..1....0..0..0....0..0..1....0..1..0....1..1..1....0..0..1....0..0..1 %e A254171 ..0..1..0....0..0..0....1..1..1....0..0..1....0..1..0....0..0..0....0..0..0 %e A254171 ..1..1..0....0..1..0....0..0..0....0..0..0....0..1..0....0..1..0....0..0..0 %e A254171 ..1..0..0....0..0..0....0..1..0....0..1..0....0..1..1....1..1..1....1..0..0 %e A254171 ..1..0..1....0..0..1....0..1..1....0..1..0....0..0..1....1..0..0....1..1..0 %e A254171 ..1..0..1....1..0..1....0..1..0....0..1..0....0..0..1....1..1..0....1..0..1 %K A254171 nonn %O A254171 1,1 %A A254171 _R. H. Hardin_, Jan 26 2015