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A215440 Numbers k such that 3^k + k^3 - 1 is prime. 1
1, 3, 5, 9, 65, 71, 225, 269, 651, 843, 1971, 4851, 13667, 13961, 33309, 168111 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(17) > 2*10^5. - Robert Price, Apr 15 2014

LINKS

Table of n, a(n) for n=1..16.

MATHEMATICA

Select[Range[0, 3000], PrimeQ[3^# + #^3 - 1] &]

PROG

(MAGMA) [n: n in [0..800] | IsPrime(3^n + n^3 - 1)]

(PARI) is(n)=ispseudoprime(3^n+n^3-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A215435.

Sequence in context: A125708 A055289 A124974 * A163550 A123220 A098339

Adjacent sequences:  A215437 A215438 A215439 * A215441 A215442 A215443

KEYWORD

nonn

AUTHOR

Vincenzo Librandi, Sep 03 2012

EXTENSIONS

a(12)-a(16) from Robert Price, Apr 15 2014

STATUS

approved

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Last modified January 26 05:10 EST 2020. Contains 331273 sequences. (Running on oeis4.)