|
%I #5 Dec 18 2015 18:17:45
%S 1,1,9,369,121367,286168923,5151383545261,720374496860187931,
%T 798423610752730381095001
%N Number of lower triangles of an n X n -4..4 array with all row and column sums zero
%C Column 4 of A195522
%e Some solutions for n=4
%e ..0........0........0........0........0........0........0........0
%e ..3-3......4-4......3-3.....-3.3.....-3.3.....-1.1.....-2.2......1-1
%e .-3.4-1....0.0.0...-3.0.3....2-1-1....2-3.1....0-4.4...-2.1.1....1.0-1
%e ..0-1.1.0.-4.4.0.0..0.3-3.0..1-2.1.0..1.0-1.0..1.3-4.0..4-3-1.0.-2.1.1.0
%K nonn
%O 1,3
%A _R. H. Hardin_ Sep 20 2011
| 