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 A220334 #5 Jul 23 2025 01:04:23 %S A220334 1,1081,84196,10004541,1026529800,119808040854 %N A220334 Equals two maps: number of 7Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..1 7Xn array. %C A220334 Row 7 of A220328 %e A220334 Some solutions for n=3 %e A220334 ..0..1..0....0..1..0....0..0..0....0..1..0....0..0..1....0..1..1....0..1..1 %e A220334 ..0..1..0....1..1..0....0..0..0....0..1..0....1..0..0....0..1..0....0..0..1 %e A220334 ..1..0..0....1..0..0....1..1..1....1..0..0....0..0..0....1..1..0....1..0..0 %e A220334 ..0..1..1....0..1..0....0..0..0....0..1..1....0..0..0....0..1..0....1..0..0 %e A220334 ..1..0..0....0..0..0....0..0..0....1..0..0....0..1..1....1..1..0....0..1..0 %e A220334 ..1..0..0....0..0..1....0..0..0....0..0..0....1..0..1....0..1..0....0..0..0 %e A220334 ..0..1..0....0..1..0....0..1..0....1..0..0....1..1..0....1..0..0....1..0..0 %K A220334 nonn %O A220334 1,2 %A A220334 _R. H. Hardin_ Dec 10 2012