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 A265190 #5 Aug 12 2016 07:05:16 %S A265190 0,0,17,774,76035,10866362,2130866037,551607137250,182413680759659, %T A265190 75075411378226014,37647855624072772341 %N A265190 Number of nX3 arrays containing 3 copies of 0..n-1 with no equal horizontal or antidiagonal neighbors and new values introduced sequentially from 0. %C A265190 Column 3 of A265192. %e A265190 Some solutions for n=4 %e A265190 ..0..1..0....0..1..0....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2 %e A265190 ..2..1..3....0..2..1....3..0..3....3..0..1....3..0..2....2..3..1....3..0..2 %e A265190 ..2..1..2....3..2..3....1..2..0....3..2..0....1..3..1....2..0..3....3..1..2 %e A265190 ..3..0..3....1..2..3....1..3..2....1..3..2....0..3..2....3..0..1....3..0..1 %Y A265190 Cf. A265192. %K A265190 nonn %O A265190 1,3 %A A265190 _R. H. Hardin_, Dec 04 2015