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A113480 Numbers n such that 17^n + 2 is prime. 8
0, 1, 105, 369, 25521 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Only numbers of the form 6k-5 and 6k-3 need be tested.

No further terms < 100000. - Ray Chandler, Jul 31 2011

a(6) > 2*10^5. - Robert Price, Oct 23 2014

LINKS

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

Henri & Renaud Lifchitz, PRP Records.

MATHEMATICA

Do[If[PrimeQ[17^n + 2], Print[n]], {n, 0, 2500}] (* Stefan Steinerberger, Jan 28 2006 *)

PROG

(PARI) g2(n)= { print1(0", "); forstep(x=1, n, 6, if(ispseudoprime(17^x+2), print1(x", ")); if(ispseudoprime(17^(x+2)+2), print1(x+2", ")) ) }

CROSSREFS

Sequence in context: A147576 A145752 A195266 * A190577 A102792 A013594

Adjacent sequences:  A113477 A113478 A113479 * A113481 A113482 A113483

KEYWORD

nonn

AUTHOR

Cino Hilliard, Jan 09 2006

EXTENSIONS

25521 from Ray Chandler, Jul 30 2011

STATUS

approved

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Last modified August 19 20:20 EDT 2019. Contains 326133 sequences. (Running on oeis4.)