A145483 - OEIS

%I #9 Jan 23 2017 19:15:47

%S 13,17,23,41,47,53,101,107,131,137,167,191,227,233,251,257,263,293,

%T 311,353,383,431,443,467,503,521,557,563,587,593,641,653,761,773,797,

%U 821,947,977,1013,1031,1061,1181,1187,1217,1223,1277,1283,1301,1307,1361

%N Primes p such that 2p - 23 is prime.

%H Ivan Neretin, <a href="/A145483/b145483.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = 2*A145477(n) - 23.

%t aa = {}; k = 23; Do[If[PrimeQ[(k + Prime[n])/2], AppendTo[aa, k + Prime[n])/2]], {n, 1, 500}];aa

%t (* Second program: *)

%t Select[Prime@ Range@ 240, And[PrimeQ@ #, # > 0] &[2 # - 23] &] (* _Michael De Vlieger_, Jan 23 2017 *)

%Y Cf. A063908-A063913, A092109, A145471-A145490.

%K nonn

%O 1,1

%A _Artur Jasinski_, Oct 11 2008