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 A207418 #7 Jul 22 2025 20:23:58 %S A207418 31,961,4719,24317,175903,891720,4094666,21072638,99746042,440141222, %T A207418 2003254604,8937597494,38381074339,165425593855,709144263593, %U A207418 2981321572403,12486729646315,52162085656079,215733902493821 %N A207418 Number of nX7 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically. %C A207418 Column 7 of A207419 %H A207418 R. H. Hardin, <a href="/A207418/b207418.txt">Table of n, a(n) for n = 1..210</a> %e A207418 Some solutions for n=4 %e A207418 ..1..1..1..0..0..0..0....1..1..1..1..1..0..0....0..1..1..1..0..0..0 %e A207418 ..0..1..1..1..0..0..0....1..1..1..0..0..0..0....1..1..1..0..1..1..0 %e A207418 ..0..0..0..0..0..0..0....0..1..1..0..0..0..0....0..0..0..0..0..0..0 %e A207418 ..1..0..0..0..0..0..0....0..0..0..0..0..0..0....0..0..0..0..0..0..0 %K A207418 nonn %O A207418 1,1 %A A207418 _R. H. Hardin_ Feb 17 2012