cp's OEIS Frontend

A208020 Number of n X 5 nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal, vertical, diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).

%I A208020 #8 Jun 25 2017 17:14:36
%S A208020 15,1657,5252041,80318704605,3662498214110836,387950830575476495043,
%T A208020 81811898713607232898679186,30915192640251267259536636853106,
%U A208020 19388812191991157504565482403825817325,19036318336696557481934278608884237849314405
%N A208020 Number of n X 5 nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal, vertical, diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).
%H A208020 Andrew Howroyd, <a href="/A208020/b208020.txt">Table of n, a(n) for n = 1..50</a>
%e A208020 Some solutions for n=4
%e A208020 ..0..1..0..1..0....0..1..2..0..1....0..1..0..1..0....0..1..0..1..0
%e A208020 ..2..3..2..3..4....2..3..4..3..2....2..3..2..3..2....2..3..2..3..2
%e A208020 ..0..4..1..0..1....1..0..1..0..1....0..1..0..1..0....0..1..4..0..1
%e A208020 ..2..3..2..3..2....2..3..2..3..2....2..3..2..3..2....2..3..2..3..2
%Y A208020 Column 5 of A208021.
%K A208020 nonn
%O A208020 1,1
%A A208020 _R. H. Hardin_, Feb 22 2012
%E A208020 Terms a(6) and beyond from _Andrew Howroyd_, Jun 25 2017