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 A184367 #7 Jul 22 2025 09:31:30 %S A184367 21,2755,2167173,10378244309,301753233626727,53293289955084658949, %T A184367 57168347029530545962203193,372482322079037724494019844619359 %N A184367 1/3 the number of (n+1)X(n+1) 0..2 arrays with every 2X2 subblock having at least two equal elements connected horizontally or vertically. %C A184367 Diagonal of A184376 %e A184367 Some solutions for 3X3 with a(1,1)=0 %e A184367 ..0..1..2....0..2..1....0..0..2....0..0..2....0..0..1....0..2..1....0..1..0 %e A184367 ..2..1..1....1..1..1....2..2..2....0..0..2....2..0..2....0..0..1....0..1..2 %e A184367 ..1..1..2....0..1..1....0..1..0....1..1..2....2..0..0....0..2..1....2..1..1 %K A184367 nonn %O A184367 1,1 %A A184367 _R. H. Hardin_ Jan 12 2011