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

Author

M. F. Hasler, Oct 19 2013

Keywords

• nonn
• easy

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.

Examples

			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.
		

Links

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

Crossrefs

Cf. A217622.

Programs

Mathematica

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

PARI

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

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