A077622 Number of numbers <= prime(n)# having n prime factors (with multiplicity), where prime(n)# = A002110(n) is the n-th primorial.
1, 2, 7, 27, 190, 1621, 17271, 200536, 2757881, 47108763, 843069901, 17797435824
Offset: 1
Keywords
Examples
a(3)=7, as there are 7 numbers <= prime(3)# = 2*3*5 = 30 having 3 prime factors: 8=2*2*2, 12=2*2*3, 18=2*3*3, 20=2*2*5, 27=3*3*3, 28=2*2*7 and 30=2*3*5.
Crossrefs
Cf. A001222.
Extensions
17271 from Sascha Kurz, Jan 04 2003
a(8)-a(11) from Donovan Johnson, Nov 15 2009
a(12) from Donovan Johnson, Jul 16 2011
Comments