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A247962 Numbers n such that 51^n + 2 is prime. 2
0, 1, 5, 6, 15, 24, 25, 66, 72, 309, 330, 594, 1000, 1142, 1882, 2482, 2725, 30106, 65176, 85334 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Numbers ending with 8 are not in the sequence. - Bruno Berselli, Oct 02 2014

a(21) > 2*10^5. - Robert Price, Jul 07 2015

LINKS

Table of n, a(n) for n=1..20.

Henri & Renaud Lifchitz, PRP Top Records, Search for 51^n+2.

MAPLE

A247962:=n->`if`(isprime(51^n+2), n, NULL): seq(A247962(n), n=0..500); # Wesley Ivan Hurt, Oct 02 2014

MATHEMATICA

Select[Range[0, 2000], PrimeQ[51^# + 2] &]

PROG

(MAGMA) [n: n in [0..300]| IsPrime( 51^n + 2 )];

(PARI) is(n)=ispseudoprime(51^n+2) \\ Charles R Greathouse IV, Jun 06 2017

CROSSREFS

Cf. similar sequences listed in A247957.

Sequence in context: A030533 A227066 A115908 * A241307 A185876 A091020

Adjacent sequences:  A247959 A247960 A247961 * A247963 A247964 A247965

KEYWORD

nonn,more

AUTHOR

Vincenzo Librandi, Oct 02 2014

EXTENSIONS

a(16)-a(20) from Robert Price, Jul 07 2015

STATUS

approved

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Last modified June 26 10:12 EDT 2019. Contains 324375 sequences. (Running on oeis4.)