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 A219679 #7 Jul 23 2025 00:35:51 %S A219679 3,4,31,427,8964,344926,35011623,10451333258 %N A219679 Number of n X n arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 n X n array. %C A219679 Diagonal of A219686 %e A219679 Some solutions for n=3 %e A219679 ..1..0..0....1..0..0....1..1..0....2..0..0....0..0..0....1..0..0....0..0..0 %e A219679 ..1..0..0....1..0..0....1..0..0....2..0..0....0..0..0....0..0..0....0..0..0 %e A219679 ..1..1..2....2..2..2....2..0..0....2..2..2....2..2..2....0..0..1....2..1..1 %K A219679 nonn %O A219679 1,1 %A A219679 _R. H. Hardin_ Nov 25 2012