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 A265243 #6 Aug 12 2016 06:53:58 %S A265243 1,68,4716,359172,29189088,2481226704,217953360768,19628937626304, %T A265243 1802766369904128,168204846247664640,15899323155731638272, %U A265243 1519290122351403276288,146525430785641038692352 %N A265243 Number of 4Xn arrays containing n copies of 0..4-1 with no equal antidiagonal neighbors and new values introduced sequentially from 0. %C A265243 Row 4 of A265241. %H A265243 R. H. Hardin, <a href="/A265243/b265243.txt">Table of n, a(n) for n = 1..30</a> %e A265243 Some solutions for n=3 %e A265243 ..0..0..1....0..0..1....0..1..2....0..1..0....0..1..1....0..1..2....0..0..0 %e A265243 ..2..2..3....2..3..2....0..1..3....0..2..3....2..2..2....3..1..0....1..2..3 %e A265243 ..3..1..1....1..3..2....0..2..3....1..2..2....3..3..3....0..2..3....1..2..2 %e A265243 ..0..2..3....1..0..3....3..1..2....3..3..1....1..0..0....3..2..1....1..3..3 %Y A265243 Cf. A265241. %K A265243 nonn %O A265243 1,2 %A A265243 _R. H. Hardin_, Dec 06 2015