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 A251796 #6 Jun 02 2025 10:31:45 %S A251796 6627,348679,17195593,873945739,44356434596,2255553135793, %T A251796 114701510008550,5833986692886877,296731470002944944, %U A251796 15092940450644308394,767684502371802140711,39047592997403421809265 %N A251796 Number of (n+1)X(3+1) 0..3 arrays with no 2X2 subblock having x11-x00 less than x10-x01. %C A251796 Column 3 of A251801 %H A251796 R. H. Hardin, <a href="/A251796/b251796.txt">Table of n, a(n) for n = 1..210</a> %e A251796 Some solutions for n=1 %e A251796 ..0..0..0..2....0..1..0..3....2..2..1..1....1..0..2..2....1..2..2..3 %e A251796 ..0..1..2..3....1..0..3..1....1..2..3..3....1..3..3..3....0..1..1..0 %K A251796 nonn %O A251796 1,1 %A A251796 _R. H. Hardin_, Dec 09 2014