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

Table of n, a(n) for n=1..7.

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

Cf. A070518-A070526.

Sequence in context: A370407 A094313 A214914 * A158652 A127074 A328322

Adjacent sequences: A070524 A070525 A070526 * A070528 A070529 A070530

Keyword

more,nonn

Author

Labos Elemer, May 02 2002

Extensions

One more term from Max Alekseyev, May 29 2009

Status

approved