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 A212944 #6 Jul 22 2025 23:01:03 %S A212944 1,7,181,10311,1016501,152747323,32383630189,9192184928839, %T A212944 3362887443335365,1540205755192368507,863047803911184565037, %U A212944 580733337119861320815291,462049013032247252827284109 %N A212944 Number of 2Xn 0..n-1 arrays with no column j greater than or equal to than column j-1 in all rows. %C A212944 Row 2 of A212943 %H A212944 R. H. Hardin, <a href="/A212944/b212944.txt">Table of n, a(n) for n = 1..19</a> %e A212944 Some solutions for n=4 %e A212944 ..1..1..2..2....1..0..3..3....3..3..0..3....0..1..0..1....0..0..1..3 %e A212944 ..3..2..1..0....1..3..2..0....1..0..2..0....3..2..3..1....3..2..1..0 %K A212944 nonn %O A212944 1,2 %A A212944 _R. H. Hardin_ May 31 2012