1,1

Table of n, a(n) for n=1..79.

a(n) = A099981(n) - A075818(n).

a(1) = -2 because ((2*1)-th semiprime) - 2*(1st semiprime) = 6 - 2*4 = -2.

Cf. A066066.

Sequence in context: A086454 A339492 A069360 * A213023 A068050 A210967

Adjacent sequences: A175506 A175507 A175508 * A175510 A175511 A175512

sign

Juri-Stepan Gerasimov, Jun 02 2010

Entries checked by R. J. Mathar, Aug 12 2010

approved