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 A207176 #8 Jul 22 2025 20:04:47 %S A207176 2,16,241,11227,1507355,567046841,600838995529,1782395103048207, %T A207176 14875073639322545780,349568074576274459361253, %U A207176 23097327995486146831078764702,4291548218733300058236161251915163 %N A207176 Number of n X n 0..1 arrays avoiding 0 0 0 horizontally and 0 1 0 vertically. %C A207176 Diagonal of A207182 %e A207176 Some solutions for n=4 %e A207176 ..1..0..0..1....0..1..1..0....1..1..0..1....1..1..1..1....1..1..0..1 %e A207176 ..1..0..0..1....0..0..1..0....1..0..1..1....1..1..1..1....0..0..1..0 %e A207176 ..1..1..1..1....0..0..1..1....0..0..1..1....1..1..1..1....0..1..1..1 %e A207176 ..1..1..1..1....1..0..0..1....0..0..1..1....1..1..1..1....1..1..1..1 %K A207176 nonn %O A207176 1,1 %A A207176 _R. H. Hardin_ Feb 15 2012