1,1

Semiprime analogue of primorial (A002110). Equivalent for product of what A062198 is for sum. Bigomega(a(n)) = the number of not necessarily distinct prime factors of a(n) = A001222(a(n)) = A005843(n) = 2*n.

a(n) = Prod[from i = 1 to n]A001358(i).

a(10) = 4*6*9*10*14*15*21*22*25*26 = 136216080000, the product of the first 10 semiprimes.

Cf. A001358, A002110, A062198.

Sequence in context: A050388 A010039 A162314 this_sequence A077555 A166881 A145237

Adjacent sequences: A112138 A112139 A112140 this_sequence A112142 A112143 A112144

easy,nonn

Jonathan Vos Post (jvospost3(AT)gmail.com), Nov 28 2005