A212042 - OEIS

A212042

Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any element within a city block distance of two, and containing the value n(n+1)/2-5

%I #4 Dec 18 2015 18:18:10

%S 0,0,5,447,94131,5054845,109065807,1339229741,11235618109

%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 element within a city block distance of two, and containing the value n(n+1)/2-5

%C Column 4 of A212044

%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 ..3.4.0....3.0.4....3.4.0....3.0.4....3.4.5....3.4.5....3.0.4....3.4.5

%e ..0.5.3.4..5.1.2.5..5.6.3.5..5.6.7.5..5.0.6.2..2.1.0.2..5.1.6.2..6.7.2.1

%K nonn

%O 1,3

%A _R. H. Hardin_ Apr 28 2012