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 A251798 #6 Jun 02 2025 10:31:58 %S A251798 187000,27291608,3934266515,594938582014,90717637876583, %T A251798 13902663302194715,2134102396738819286,327882361916540095426, %U A251798 50392001598117407333828,7746165276288696623011479 %N A251798 Number of (n+1)X(5+1) 0..3 arrays with no 2X2 subblock having x11-x00 less than x10-x01. %C A251798 Column 5 of A251801 %H A251798 R. H. Hardin, <a href="/A251798/b251798.txt">Table of n, a(n) for n = 1..210</a> %e A251798 Some solutions for n=1 %e A251798 ..0..2..0..1..3..2....0..0..3..1..1..1....2..2..2..2..2..3....0..2..2..2..2..3 %e A251798 ..2..0..2..2..0..3....2..3..0..2..2..3....0..0..1..2..2..3....0..0..0..0..3..3 %K A251798 nonn %O A251798 1,1 %A A251798 _R. H. Hardin_, Dec 09 2014