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 A281610 #3 Jan 25 2017 10:44:14 %S A281610 365,52193,736757,32354824,1421127262,56764280423,2352459742664, %T A281610 97337283237331,4014393674152359 %N A281610 Number of 7Xn 0..2 arrays with no element equal to more than one of its horizontal, diagonal or antidiagonal neighbors and with new values introduced in order 0 sequentially upwards. %C A281610 Row 7 of A281605. %e A281610 Some solutions for n=2 %e A281610 ..0..1. .0..0. .0..0. .0..1. .0..1. .0..1. .0..0. .0..1. .0..1. .0..1 %e A281610 ..0..1. .1..2. .1..1. .2..0. .0..2. .0..2. .1..1. .2..1. .2..1. .2..1 %e A281610 ..2..0. .0..1. .0..0. .1..2. .0..1. .0..2. .2..2. .1..0. .2..0. .2..0 %e A281610 ..1..2. .2..0. .2..1. .1..2. .2..1. .0..2. .0..0. .2..0. .2..1. .0..1 %e A281610 ..1..0. .2..0. .2..0. .2..1. .2..0. .1..0. .1..2. .0..2. .1..0. .2..1 %e A281610 ..2..0. .0..1. .1..0. .2..1. .0..1. .1..0. .1..0. .0..2. .1..2. .0..2 %e A281610 ..1..0. .0..2. .0..1. .2..0. .0..1. .2..2. .1..2. .0..2. .2..0. .0..1 %Y A281610 Cf. A281605. %K A281610 nonn %O A281610 1,1 %A A281610 _R. H. Hardin_, Jan 25 2017