0,1

Semiprime analog of A065415.

The logarithm is -sum_{s>=2} sum_{j=1..floor[s/(1+r)]} binomial(s-r*j-1,j-1)*P_2(s)/j at r=3, where P_k(s) are the k-almost prime zeta functions of arXiv:0803.0900.

0.993521589710505460675409269.. = (1-1/192)*(1-1/1080)*(1-1/5832)*...

Sequence in context: A110639 A011211 A074879 this_sequence A140416 A153505 A088398

Adjacent sequences: A146487 A146488 A146489 this_sequence A146491 A146492 A146493

nonn,cons,less

R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 13 2009