A182326 - OEIS

%I #5 Dec 18 2015 18:17:27

%S 1,1,10,1744,7122884,932561028624

%N Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any horizontal, vertical, diagonal or antidiagonal neighbor

%e Some solutions for n=4

%e ..0........0........0........0........0........0........0........0

%e ..1.2......1.2......1.2......1.2......1.2......1.2......1.2......1.2

%e ..3.0.4....0.3.4....3.0.1....3.4.3....0.3.4....3.4.5....3.0.1....0.3.1

%e ..5.1.2.5..5.6.2.0..2.4.3.5..2.0.2.1..1.5.2.5..0.6.7.0..4.5.6.2..4.5.2.5

%K nonn

%O 1,3

%A _R. H. Hardin_ Apr 24 2012