A230460 - OEIS

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

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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))