A260073 Number of triples {x, y, x mod y} of three distinct divisors of n.

0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 3, 0, 1, 0, 0, 0, 3, 0, 3, 1, 1, 0, 6, 0, 1, 0, 2, 0, 8, 0, 0, 0, 1, 0, 9, 0, 1, 1, 5, 0, 9, 0, 2, 0, 1, 0, 10, 0, 3, 0, 3, 0, 6, 1, 4, 1, 1, 0, 23, 0, 1, 2, 0, 0, 7, 0, 3, 0, 6, 0, 18, 0, 1

Offset: 1

Author

Juri-Stepan Gerasimov, Aug 19 2015

Keywords

• nonn

Comments

a(n) = 0 if n is a prime power. - Charles R Greathouse IV, Aug 20 2015

Examples

			a(6) = 1 because x = 3, y = 2, x mod y = 1 and 3, 2, 1 are distinct divisors of 6.
		

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A027750.

Programs

PARI

a(n)=my(d=divisors(n),x,y,z); sum(i=2,#d-2, y=d[i]; sum(j=i+1,#d-1, x=d[j]; z=x%y; z && n%z==0)) \\ Charles R Greathouse IV, Aug 20 2015

Extensions

Corrected and edited by Charles R Greathouse IV, Aug 20 2015