A070527 Numbers k such that cyclotomic(k, 2^k) is a prime number.

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

Offset: 1

Author

Labos Elemer, May 02 2002

Keywords

• more
• nonn

Comments

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

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

Examples

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

Crossrefs

Cf. A070518-A070526.

Programs

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 *)

PARI

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

Extensions

One more term from Max Alekseyev, May 29 2009