Voozh

A070527

Numbers k such that cyclotomic(k, 2^k) is a prime number.

2, 3, 4, 7, 40, 59, 140

OFFSET

1,1

COMMENTS

No other terms below 300. - Max Alekseyev, May 29 2009

No other terms below 760. - Lucas A. Brown, Dec 16 2020

LINKS

EXAMPLE

4 is a term because cyclotomic(4,16) = 1 + 16^2 = 257 is prime.

MATHEMATICA

Do[s=Cyclotomic[n, 2^n]; If[PrimeQ[s], Print[n]], {n, 1, 1000}]

Select[Range[150], PrimeQ[Cyclotomic[#, 2^#]]&] (* Harvey P. Dale, Aug 12 2023 *)

PROG

(PARI) isok(k) = isprime(polcyclo(k, 2^k)); \\ Michel Marcus, Dec 17 2020

CROSSREFS

KEYWORD

more,nonn

AUTHOR

Labos Elemer, May 02 2002

EXTENSIONS

One more term from Max Alekseyev, May 29 2009

STATUS

approved

URL: https://oeis.org/A070527