A091992 Numbers n such that 5*n-3 and 5*n+3 are both primes.

2, 4, 8, 10, 14, 20, 22, 32, 34, 46, 52, 56, 62, 70, 74, 92, 112, 118, 122, 130, 136, 146, 172, 176, 190, 196, 218, 220, 224, 238, 244, 256, 260, 274, 286, 290, 298, 322, 332, 350, 356, 374, 382, 398, 400, 428, 442, 448, 454, 458, 476, 484, 494, 532, 536, 538

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..5000

Formula

a(n) = 2*A093013(n).

Mathematica

Select[Range[600], PrimeQ[5*# -3] && PrimeQ[5*# +3] &] (* G. C. Greubel, Feb 05 2019 *)

Prog

(PARI) for(n=1, 538, if(isprime(5*n-3)&&isprime(5*n+3), print1(n, ", "))) \\ Jinyuan Wang, Feb 06 2019

Crossrefs

Equals twice A093013.

Sequence in context: A087915 A088967 A200566 * A206037 A242247 A089033

Adjacent sequences: A091989 A091990 A091991 * A091993 A091994 A091995

Keyword

nonn

Author

Giovanni Teofilatto, Mar 17 2004

Extensions

Corrected and extended by Ray Chandler, Mar 19 2004

Status

approved