A225587 a(n) is the smallest prime of the form prime(n)*q + prime(n) + q, where q is an odd prime.

11, 23, 23, 31, 47, 83, 71, 79, 191, 179, 127, 151, 167, 263, 191, 431, 239, 743, 271, 431, 443, 479, 503, 359, 587, 1223, 1871, 431, 439, 683, 6143, 1583, 827, 839, 599, 607, 631, 983, 2351, 2087, 719, 727, 1151, 1163, 1187, 2399, 2543, 2687, 911, 919

Offset

1,1

Comments

The odd primes q minimizing prime(n)*q + prime(n) + q are listed in A225581.

Links

John-Å. W. Olsen, Table of a(n), for n = 1..1000

Formula

a(n) = (1+prime(n))*A225581(n) + prime(n).

Example

a(1) = 11 because prime(1) = 2 and the minimal prime of the form 2*q+2+q with q an odd prime is 11 = 2*3+2+3.

Mathematica

a[n_] := Block[{q = 3, v, p = Prime@n}, While[! PrimeQ[v = p q + p + q], q = NextPrime@q]; v]; Array[a, 50] (* Giovanni Resta, May 11 2013 *)

Crossrefs

Cf. A225581, A000040.

Sequence in context: A352868 A119815 A046624 * A143584 A134773 A226662

Adjacent sequences: A225584 A225585 A225586 * A225588 A225589 A225590

Keyword

nonn,easy

Author

John-Å. W. Olsen, May 11 2013

Extensions

a(26)-a(50) from Giovanni Resta, May 11 2013

Status

approved