A232558 a(1)=5, q=a(n) is the smallest prime > a(n-1) such that q-2*n = p prime.

5, 7, 11, 13, 17, 19, 31, 47, 59, 61, 83, 97, 109, 131, 137, 139, 173, 193, 211, 233, 239, 241, 257, 271, 277, 281, 283, 307, 389, 397, 409, 431, 433, 457, 467, 491, 523, 563, 569, 571, 653, 661, 673, 701, 709, 733, 821, 823, 859, 887, 911, 967, 983, 991

Offset: 1

Author

Pierre CAMI, Nov 26 2013

Keywords

• nonn

Comments

Conjecture: the sequence is infinite.

Remarks: the primes p appears in increasing order but with repetition, all the primes are not present in p,q.

Examples

			5-3=2 a(1)=5
7-3=4 a(2)=7
11-5=6 a(3)=11
13-5=8 a(4)=13
17-7=10 a(5)=17
		

Links

• Pierre CAMI, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A020483

Programs

Mathematica

a[1]=5;a[n_]:=a[n]=(For[k=a[n-1]+2,!(k>2n&&PrimeQ[k]&&PrimeQ[k-2n]),k++];k)