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A228225 Numbers n such that (17^n + 3^n)/20 is prime. 1
37, 641, 2521, 7993, 41213 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms are primes.

a(6) > 10^5.

LINKS

Table of n, a(n) for n=1..5.

MATHEMATICA

k=17; Do[ p=Prime[n]; f=(3^p+k^p)/(k+3); If[ PrimeQ[f], Print[p]], {n, 1, 9592} ]

PROG

(PARI) is(n)=ispseudoprime((17^n+3^n)/20) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A128073, A224507, A128075, A227046.

Sequence in context: A056217 A105464 A140764 * A156923 A104180 A010953

Adjacent sequences:  A228222 A228223 A228224 * A228226 A228227 A228228

KEYWORD

hard,more,nonn

AUTHOR

Robert Price, Aug 16 2013

STATUS

approved

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Last modified March 19 13:34 EDT 2019. Contains 321330 sequences. (Running on oeis4.)