A062701 Index of factorial primes of the form k! + 1.

1, 2, 4, 2428957

Offset

1,2

Links

Table of n, a(n) for n=1..4.

Formula

a(n) = PrimePi(A002981(n)!+1).

Example

The exact subscript of the 5th prime [1 + 27! = 10888869450418352160768000001] is not yet available.

Crossrefs

Cf. A000720, A002981, A002982, A055490, A088332.

Sequence in context: A274990 A079236 A138852 * A341805 A252783 A192225

Adjacent sequences: A062698 A062699 A062700 * A062702 A062703 A062704

Keyword

hard,nonn,more

Author

Labos Elemer, Jul 11 2001

Extensions

Offset 1 from Michel Marcus, Aug 29 2019

Status

approved