A066851 Number of ordered solutions (x,y,z) to xy + yz + zx = n with x,y,z >= 1.

0, 0, 1, 0, 3, 0, 3, 3, 3, 0, 9, 1, 3, 6, 6, 3, 9, 0, 9, 9, 6, 0, 15, 6, 3, 12, 10, 3, 15, 0, 15, 12, 6, 6, 18, 9, 3, 12, 18, 6, 21, 0, 9, 21, 9, 6, 27, 7, 9, 12, 18, 9, 15, 12, 18, 24, 6, 0, 33, 6, 15, 18, 21, 12, 18, 12, 9, 27, 18, 0, 39, 9, 9, 24, 19, 21, 18, 0, 27, 27, 18, 6, 33, 18, 6

Offset: 1

Author

Colin Mallows, Jan 24 2002

Keywords

• easy
• nonn

Examples

			a(5) = 3 since there are solutions (2,1,1), (1,2,1), (1,1,2).
		

Links

• T. D. Noe, Table of n, a(n) for n=1..1000

Crossrefs

a(A025052(n))=0. Cf. A066958.

Extensions

More terms from Vladeta Jovovic, Jan 25 2002