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A091992 Numbers n such that 5*n-3 and 5*n+3 are both primes. 2
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified May 25 20:58 EDT 2020. Contains 334597 sequences. (Running on oeis4.)