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A243471 Primes p such that p^6 - p^5 + 1 is prime. 2
3, 31, 73, 181, 367, 373, 523, 631, 733, 1021, 1039, 1171, 1489, 1723, 1777, 2203, 2557, 2683, 3121, 3187, 3319, 4441, 4591, 4621, 4801, 4957, 5113, 5167, 5323, 5431, 5659, 5839, 5851, 5857, 6883, 7057, 7129, 7297, 7309, 7477, 7993, 8017, 8209, 8221, 8689, 8821 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

K. D. Bajpai, Table of n, a(n) for n = 1..5457

EXAMPLE

31 appears in the sequence because it is prime and 31^6 - 31^5  + 1 = 858874531 is also prime.

73 appears in the sequence because it is prime and 73^6 - 73^5  + 1 = 149261154697 is also prime.

MAPLE

A243471 := proc() local a, b; a:=ithprime(n); b:= a^6-a^5+1; if isprime (b) then RETURN (a); fi; end: seq(A243471 (), n=1..2000);

MATHEMATICA

c=0; Do[k=Prime[n]; If[PrimeQ[k^6-k^5+1], c++; Print[c, " ", k]], {n, 1, 200000}];

CROSSREFS

Cf. A000040, A091567, A053182, A053183, A053184, A238136.

Sequence in context: A244916 A031916 A137185 * A152417 A182232 A294973

Adjacent sequences:  A243468 A243469 A243470 * A243472 A243473 A243474

KEYWORD

nonn

AUTHOR

K. D. Bajpai, Jun 05 2014

STATUS

approved

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Last modified August 8 02:45 EDT 2020. Contains 336290 sequences. (Running on oeis4.)