A007441 1 + Sum_{n>=1} a_n x^n = Product_{n>=1} (1-x^n)^prime(n).

1, -2, -2, 1, 3, 7, 5, 6, -10, -27, -50, -42, -30, 41, 148, 241, 345, 303, 167, -275, -858, -1685, -2342, -2813, -2316, -536, 2914, 8228, 14531, 20955, 24370, 22393, 10265, -13839, -53386, -104364, -161593, -209463, -228141, -188750, -62023, 177547, 541310, 1009998, 1527972, 1976120, 2189974

Offset: 0

Author

N. J. A. Sloane

Keywords

• sign

References

• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A030009, A030010, A061150, A061151, A061152.

Formula

a(n) = (1/n)*Sum_{k=1..n} a(n-k)*b(k), k>0, a(0)=1, b(k)=-Sum_{d|k} d*prime(d), cf. A061150.

Extensions

Better description from Vladeta Jovovic, Apr 16 2001