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A039687 Primes of form 3*2^n+1. 9
7, 13, 97, 193, 769, 12289, 786433, 3221225473, 206158430209, 6597069766657, 221360928884514619393, 2353913150770005286438421033702874906038383291674012942337 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..12.

S. W. Golomb, Properties of the sequence 3.2^n+1, Math. Comp., 30 (1976), 657-663.

MATHEMATICA

Select[Table[6 2^n+1, {n, 0, 250}], PrimeQ] [From Harvey P. Dale, Dec. 17, 2010]

CROSSREFS

For more terms see A002253. These are the primes in A004119 (or A181565).

Sequence in context: A132373 A110293 A253333 * A001544 A202152 A136720

Adjacent sequences:  A039684 A039685 A039686 * A039688 A039689 A039690

KEYWORD

nonn

AUTHOR

Felice Russo

STATUS

approved

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Last modified September 4 21:18 EDT 2015. Contains 261338 sequences.