A145483 - OEIS

A145483

Primes p such that 2p - 23 is prime.

13, 17, 23, 41, 47, 53, 101, 107, 131, 137, 167, 191, 227, 233, 251, 257, 263, 293, 311, 353, 383, 431, 443, 467, 503, 521, 557, 563, 587, 593, 641, 653, 761, 773, 797, 821, 947, 977, 1013, 1031, 1061, 1181, 1187, 1217, 1223, 1277, 1283, 1301, 1307, 1361

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

FORMULA

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

MATHEMATICA

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

(* Second program: *)

Select[Prime@ Range@ 240, And[PrimeQ@ #, # > 0] &[2 # - 23] &] (* Michael De Vlieger, Jan 23 2017 *)

CROSSREFS