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 A219887 #5 Jul 23 2025 00:46:15 %S A219887 28,151,1069,10350,89795,764027,6337533,51044999,398508546,2994521086 %N A219887 Number of 6Xn arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 6Xn array. %C A219887 Row 6 of A219883 %e A219887 Some solutions for n=3 %e A219887 ..0..0..0....1..1..1....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A219887 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A219887 ..1..0..0....0..0..0....1..0..1....1..1..1....0..1..0....1..1..1....1..0..1 %e A219887 ..2..0..0....0..0..0....1..0..0....0..1..0....1..1..1....1..1..2....1..0..1 %e A219887 ..2..0..1....0..0..0....1..0..0....0..0..0....2..1..1....1..0..2....2..0..0 %e A219887 ..2..1..1....2..0..0....1..0..2....0..2..0....2..1..1....2..0..0....2..0..2 %K A219887 nonn %O A219887 1,1 %A A219887 _R. H. Hardin_ Nov 30 2012