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 A212946 #6 Jul 22 2025 23:01:20 %S A212946 1,175,331489,2509306671,52311221188001,2438624218076957695, %T A212946 221920456466342315024785,35805749325509532346413477679, %U A212946 9531951779328890331855321215698177 %N A212946 Number of 4Xn 0..n-1 arrays with no column j greater than or equal to than column j-1 in all rows. %C A212946 Row 4 of A212943 %H A212946 R. H. Hardin, <a href="/A212946/b212946.txt">Table of n, a(n) for n = 1..18</a> %e A212946 Some solutions for n=4 %e A212946 ..3..3..2..1....1..3..2..1....2..1..1..1....3..3..0..0....0..0..1..0 %e A212946 ..3..2..2..2....1..1..0..3....0..2..1..3....3..3..3..2....2..2..0..1 %e A212946 ..2..3..2..2....2..3..3..0....3..1..2..0....1..0..1..0....3..2..0..0 %e A212946 ..3..1..1..2....1..0..3..0....2..2..1..2....1..1..0..3....0..0..1..0 %K A212946 nonn %O A212946 1,2 %A A212946 _R. H. Hardin_ May 31 2012