A265670 Numbers n such that n^5 + n^4 + n^3 + n^2 + n - 1 is prime.

2, 8, 10, 12, 16, 18, 22, 24, 28, 32, 42, 50, 60, 68, 70, 78, 88, 104, 108, 118, 132, 138, 206, 238, 240, 242, 270, 282, 300, 306, 312, 318, 338, 372, 376, 382, 390, 394, 398, 418, 440, 452, 464, 512, 522, 532, 534, 548, 566, 586, 594, 626, 630, 636, 640, 650

Offset

1,1

Comments

All terms are even. - Altug Alkan, Dec 13 2015

Links

Table of n, a(n) for n=1..56.

Example

2 is in the sequence because 2^5 + 2^4 + 2^3 + 2^2 + 2 - 1 = 61 is prime.

Mathematica

Select[Range[700], PrimeQ[Total[#^Range[1, 5, 1]] - 1] &]

Prog

(Magma) [n: n in [0..700] | IsPrime(s) where s is n^5+n^4+n^3+n^2+n-1];
(PARI) print1(2, ", "); forcomposite(n=1, 1e4, if(ispseudoprime(n^5 + n^4 + n^3 + n^2 + n - 1), print1(n, ", "))) \\ Altug Alkan, Dec 13 2015

Crossrefs

Cf. A045546, A100331, A125964, A182424.

Sequence in context: A081693 A022298 A229090 * A297999 A287088 A296342

Adjacent sequences: A265667 A265668 A265669 * A265671 A265672 A265673

Keyword

nonn,easy

Author

Vincenzo Librandi, Dec 13 2015

Status

approved