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A059747 Numbers n such that 3*2^n - 7 is prime. 0
2, 3, 4, 5, 8, 12, 15, 17, 20, 21, 45, 48, 87, 97, 113, 120, 172, 217, 228, 276, 312, 580, 692, 1132, 1588, 1668, 2576, 2591, 3780, 4311, 4412, 6205, 11952 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Next term > 12000. Vincenzo Librandi, Sep 29 2012

LINKS

Table of n, a(n) for n=1..33.

MATHEMATICA

Do[ If[ PrimeQ[ 3*2^n - 7 ], Print[n] ], {n, 3000} ]

Select[Range[6500], PrimeQ[(3*2^# - 7)] &] (* Vincenzo Librandi, Sep 29 2012 *)

PROG

(PARI) is(n)=ispseudoprime(3*2^n-7) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A048486 A179402 A065428 * A254328 A094087 A225132

Adjacent sequences:  A059744 A059745 A059746 * A059748 A059749 A059750

KEYWORD

nonn,more

AUTHOR

Robert G. Wilson v, Feb 10 2001

EXTENSIONS

a(29)-a(32) from Vincenzo Librandi, Sep 29 2012

a(33) from Bruno Berselli, Sep 30 2012

STATUS

approved

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Last modified December 2 14:54 EST 2020. Contains 338877 sequences. (Running on oeis4.)