A185174 Number of primes less than the n-th perfect number.

3, 9, 94, 1022, 2063449, 393612920, 5586492151, 55890484019689268

Offset

1,1

Links

Table of n, a(n) for n=1..8.

Chris K. Caldwell, Perfect Number.

Chris K. Caldwell and G. L. Honaker, Jr., Prime Curios!: 3.

Formula

a(n) = 3 + Sum_{k=1..n-1} A164266(k). - Amiram Eldar, Sep 03 2024

Crossrefs

Cf. A000040, A000396, A000720, A164266.

Sequence in context: A237355 A007663 A231212 * A018695 A250302 A156336

Adjacent sequences: A185171 A185172 A185173 * A185175 A185176 A185177

Keyword

nonn,more,hard

Author

G. L. Honaker, Jr., Feb 28 2012

Extensions

a(8) from Giovanni Resta, Nov 19 2019

Status

approved