OFFSET
1,1
COMMENTS
See A250293 for more information.
FORMULA
a(n) = primepi(A250293(n)). - Hugo Pfoertner, Feb 05 2021
PROG
(PARI) isok(k) = bigomega(1 + prod(j=1, k, prime(j))) == 2; \\ Michel Marcus, Mar 30 2019
CROSSREFS
KEYWORD
more,hard,nonn
AUTHOR
Jason Earls, Jul 20 2003
EXTENSIONS
More terms from David Wasserman, Feb 09 2005
a(14)=54 from Donovan Johnson, Feb 21 2008
Offset changed to 1 by Alois P. Heinz, Jul 02 2015
a(15) added by Daniel Suteu, Mar 30 2019
a(16)-a(18) using terms of A250293 from Hugo Pfoertner, Feb 05 2021
Missing 105 inserted by Sean A. Irvine, Mar 03 2023
STATUS
approved