A230460 Prime(2*prime(n)).

7, 13, 29, 43, 79, 101, 139, 163, 199, 271, 293, 373, 421, 443, 491, 577, 647, 673, 757, 821, 839, 929, 983, 1061, 1181, 1231, 1277, 1307, 1361, 1429, 1609, 1667, 1759, 1789, 1973, 1997, 2083, 2161, 2243, 2339, 2411, 2441, 2633, 2663, 2707, 2729, 2917

Offset

1,1

Comments

A subsequence of A031378 (subsequence of A031215) and of A106349, which are both subsequences of A007821 which is the complement of A006450 in the primes A000040.

Links

M. F. Hasler, Table of n, a(n) for n = 1..1000

Formula

a(n) ~ 2n log(n) log(2n log(n)) ~ 2n (log n)^2.

a(n) = A000040(A100484(n)). - Omar E. Pol, Oct 19 2013

Example

a(3) = 29 because the third prime is 5, and 2 * 5 = 10, and then we see that the tenth prime is 29.
a(4) = 43 because the fourth prime is 7, and 2 * 7 = 14, and then we see that the fourteenth prime is 43.

Mathematica

Prime[2Prime[Range[50]]] (* Alonso del Arte, Oct 19 2013 *)

Prog

(PARI) A230460=n->prime(2*prime(n))

Crossrefs

Cf. A217622.

Sequence in context: A283650 A045463 A082221 * A182624 A096333 A133325

Adjacent sequences: A230457 A230458 A230459 * A230461 A230462 A230463

Keyword

nonn,easy

Author

M. F. Hasler, Oct 19 2013

Status

approved