A178962 Partial sums of A007322.

1, 7, 46, 366, 3647, 44205, 630956, 10350572, 191704349, 3954598099, 89888942874, 2231742720730, 60083847852539, 1743321481158041, 54226970410827160, 1800062257926566488, 63512168752599139129, 2373501269897667585631

Offset: 1

Author

Jonathan Vos Post, Dec 31 2010

Keywords

• nonn

Examples

			a(3) = 1 + 6 + 39 = 46.
		

Crossrefs

Cf. A007322, A120733.

Formula

a(n) = Sum_{i=1..n} Sum_{r>=0,s>=0} binomial(r*s+i-1,i)/2^(r+s+2).