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 A185512 #7 Jul 22 2025 09:51:32 %S A185512 31,1489,154561,80761059,96865190255,525819969687473, %T A185512 7163899183570889649,401495654334865659721795, %U A185512 61022067811287778788163474527,35442207739725827931704064596045201 %N A185512 Number of (n+1)X(n+1) 0..2 arrays with every 2X2 subblock singular. %C A185512 Diagonal of A185521 %e A185512 Some solutions for 3X3 %e A185512 ..0..1..1....0..0..2....2..1..2....1..0..1....0..0..2....1..0..2....1..0..0 %e A185512 ..0..0..0....2..0..2....0..0..0....0..0..1....1..0..2....2..0..0....2..0..2 %e A185512 ..2..2..1....2..0..0....0..2..0....1..0..0....1..0..0....2..0..1....2..0..1 %K A185512 nonn %O A185512 1,1 %A A185512 _R. H. Hardin_ Jan 29 2011