A173970 Primes p such that 2*p-NextPrime are prime numbers.

5, 7, 23, 47, 53, 73, 157, 173, 211, 233, 257, 263, 353, 373, 563, 593, 607, 619, 647, 653, 733, 947, 977, 1069, 1097, 1103, 1123, 1187, 1223, 1283, 1367, 1433, 1453, 1459, 1493, 1499, 1511, 1613, 1709, 1747, 1753, 1759, 1789, 1889, 1907, 2099, 2161, 2287

Offset

1,1

Comments

2*5-7=3, 2*7-11=3, 2*23-29=17,..

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

P:= select(isprime, [2, seq(i, i=1..10000, 2)]):
Q:= 2*P[1..-2]-P[2..-1]:
P[select(t -> isprime(Q[t]), [$1..nops(Q)])]; # Robert Israel, Jul 03 2019

Mathematica

lst={}; Do[p=Prime[n]; If[PrimeQ[2*p-Prime[n+1]], AppendTo[lst, p]], {n, 6!}]; lst
Select[Prime[Range[400]], PrimeQ[2#-NextPrime[#]]&] (* Harvey P. Dale, May 04 2021 *)

Prog

(Magma) [p:p in PrimesUpTo(2500)| IsPrime(2*p-NextPrime(p))]; // Marius A. Burtea, Jul 03 2019

Crossrefs

Sequence in context: A167936 A077242 A121182 * A028287 A293861 A321462

Adjacent sequences: A173967 A173968 A173969 * A173971 A173972 A173973

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Mar 03 2010

Status

approved