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
Examples
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.
Links
- John-Å. W. Olsen, Table of a(n), for n = 1..1000
Programs
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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 *)
Formula
a(n) = (1+prime(n))*A225581(n) + prime(n).
Extensions
a(26)-a(50) from Giovanni Resta, May 11 2013
Comments