A077272 a(n) = Sum_{d|n} d^2*2^(d-1)*(n/d-1) for n > 0.

0, 0, 1, 2, 11, 4, 57, 6, 159, 80, 441, 10, 1567, 12, 3197, 958, 8647, 16, 23301, 18, 53003, 6508, 124005, 22, 315755, 1624, 692345, 41786, 1615939, 28, 3795873, 30, 8414231, 248200, 18940065, 14978, 43126711, 36, 94634165, 1384918, 209905711, 40, 465656541

Offset: 0

Author

N. J. A. Sloane, Jun 13 2003

Keywords

• nonn

Examples

			a(4) = 1*1*3 + 4*2*1 + 16*8*0 = 11.
		

Crossrefs

Cf. A083413.

Formula

G.f.: Sum_{m>0} (m-1)*x^m*(1+2*x^m)/(1-2*x^m)^3. - Vladeta Jovovic, Jun 21 2003