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 A206995 #8 Jul 22 2025 19:54:38 %S A206995 2,16,230,6612,382349,45723467,10432265840,4567604720632, %T A206995 3835202074248503,6261201402096526687,19792947737197868206612, %U A206995 121328664454799987875557245,1441630925698363945645049021360 %N A206995 Number of n X n 0..1 arrays avoiding 0 1 0 horizontally and 0 1 1 vertically. %C A206995 Diagonal of A207000 %e A206995 Some solutions for n=4 %e A206995 ..0..1..1..0....1..0..0..0....1..0..1..1....1..0..1..1....0..0..1..1 %e A206995 ..0..1..1..1....0..1..1..0....1..0..1..1....0..0..0..1....0..1..1..1 %e A206995 ..0..1..1..0....1..0..0..1....1..1..0..0....1..0..1..1....0..0..1..1 %e A206995 ..1..0..1..1....0..1..1..0....0..0..1..1....0..0..0..1....0..1..1..1 %K A206995 nonn %O A206995 1,1 %A A206995 _R. H. Hardin_ Feb 14 2012