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A058775 Numbers n such that n * 2^(n/2) - 1 is prime. 0
2, 6, 8, 20, 54, 68, 468, 648, 1100, 1374, 14072, 17790, 20038, 27192, 42692 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

Posting to NMBRTHRY(AT)LISTSERV.NODAK.EDU by Mike Oakes Dec 30 2000 entitled "Gaussian analogues of the Cullen and Woodall primes."

LINKS

Table of n, a(n) for n=1..15.

Index entries for Gaussian integers and primes

MATHEMATICA

Do[ If[ PrimeQ[n*2^(n/2) - 1], Print[n] ], {n, 1, 100000} ]

Select[Range[2, 43000, 2], PrimeQ[#*2^(#/2)-1]&] (* Harvey P. Dale, Dec 13 2018 *)

PROG

(PARI) is(n)=isprime(n*2^(n/2)-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A289095 A290160 A290213 * A103023 A111247 A045656

Adjacent sequences:  A058772 A058773 A058774 * A058776 A058777 A058778

KEYWORD

nonn,easy

AUTHOR

Robert G. Wilson v, Jan 02 2001

STATUS

approved

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Last modified March 26 01:08 EDT 2019. Contains 321479 sequences. (Running on oeis4.)