OFFSET
1,2
FORMULA
a(n) = PrimePi(A002981(n)!+1).
EXAMPLE
The exact subscript of the 5th prime [1 + 27! = 10888869450418352160768000001] is not yet available.
CROSSREFS
KEYWORD
hard,nonn,more
AUTHOR
Labos Elemer, Jul 11 2001
EXTENSIONS
Offset 1 from Michel Marcus, Aug 29 2019
STATUS
approved