%I #6 May 03 2024 14:07:51
%S 0,0,27,5809,2484024,249499909,9339489832,186659686448
%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 or antidiagonal neighbor, and containing the value n(n+1)/2-6.
%C Column 5 of A211930.
%e Some solutions for n=4
%e ..0........0........0........0........0........0........0........0
%e ..1.0......1.2......1.2......1.2......1.0......1.2......1.0......1.2
%e ..2.3.4....3.0.2....3.0.4....3.4.3....2.3.0....0.1.3....2.3.0....3.1.0
%e ..5.0.5.1..4.3.5.6..1.5.3.0..1.2.1.3..0.4.3.5..3.4.0.3..4.5.6.0..4.2.1.2
%Y Cf. A211930.
%K nonn
%O 1,3
%A _R. H. Hardin_, Apr 25 2012