A115349 Numbers k such that (4*k^5 + 1) is prime.

1, 12, 15, 19, 27, 40, 49, 57, 60, 90, 93, 102, 132, 133, 147, 148, 153, 177, 190, 219, 240, 249, 258, 265, 274, 277, 280, 294, 313, 324, 337, 342, 363, 382, 394, 435, 448, 453, 462, 483, 489, 502, 522, 534, 538, 550, 580, 588, 609, 613, 634, 643, 648, 649

Offset

1,2

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

If k=90 then (4*90^5 + 1) = 23619600001, which is prime.
If k=133 then (4*133^5 + 1) = 166463183573, which is prime.

Maple

select(t -> isprime(4*t^5+1), [$1..1000]); # Robert Israel, Jun 19 2018

Mathematica

Do[If[PrimeQ[4*n^5 + 1], Print[n]], {n, 0, 1000}]
Select[Range[700], PrimeQ[4#^5+1]&] (* Harvey P. Dale, Aug 25 2023 *)

Prog

(Magma) [n: n in [0..1500] | IsPrime(4*n^5 + 1)]; // Vincenzo Librandi, Jan 31 2011
(PARI) is(n)=isprime((4*n^5+1)) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A115104, A001912.

Sequence in context: A329731 A350563 A120169 * A196224 A163657 A117815

Adjacent sequences: A115346 A115347 A115348 * A115350 A115351 A115352

Keyword

nonn,easy

Author

Parthasarathy Nambi, Mar 07 2006

Extensions

More terms from Craig Baribault (csb166(AT)psu.edu), Mar 14 2006 and Jessica M. Cornwall (jmc510(AT)psu.edu), Mar 22 2006

Status

approved