A126137 a(n) = pi(A037028(n)).

1, 2, 4, 8, 16, 35, 79, 184, 429, 1019, 2467, 6049, 14912, 37128, 93117, 234855, 595341, 1516234, 3877186, 9950346, 25614563, 66124777, 171141897, 443963543, 1154106845, 3005936865, 7842921261, 20496470802, 53645077679, 140599114669, 368973074566, 969455391691

Offset

0,2

Links

Amiram Eldar, Table of n, a(n) for n = 0..52

Example

a(3) = 8 since A037028(3) = 19 and 19 = the 8th prime.
a(4) = 16 since A037028(4) = 53 and 53 = the 16th prime.

Mathematica

Table[np=NextPrime[E^n]; pp=NextPrime[E^n, -1]; If[E^n-pp<np-E^n, PrimePi[pp], PrimePi[np]], {n, 0, 31}] (* James C. McMahon, Dec 25 2024 *)

Crossrefs

Cf. A000720, A037028.

Sequence in context: A244519 A247293 A337716 * A085294 A195327 A266544

Adjacent sequences: A126134 A126135 A126136 * A126138 A126139 A126140

Keyword

nonn

Author

Gary W. Adamson, Dec 18 2006

Extensions

Name edited by and more terms from Jinyuan Wang, Apr 10 2020

Offset corrected by James C. McMahon, Dec 25 2024

Status

approved