A057909 Numbers k such that 4^k + k is prime.

1, 3, 9, 15, 37, 85, 133, 225, 1233, 12793, 108889

Offset

1,2

Comments

a(11) > 20000. - Jinyuan Wang, Feb 01 2020

Links

Table of n, a(n) for n=1..11.

Mathematica

Do[ If[ PrimeQ[ 4^n + n ], Print[ n ] ], {n, 0, 3000} ]

Prog

(PARI) is(n)=ispseudoprime(4^n+n) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A052007, A057900.

Cf. A158879 (4^n + n).

Sequence in context: A013581 A350536 A133997 * A228916 A345431 A082702

Adjacent sequences: A057906 A057907 A057908 * A057910 A057911 A057912

Keyword

nonn,more

Author

Robert G. Wilson v, Nov 16 2000

Extensions

a(10) from Jinyuan Wang, Feb 01 2020

a(11) from Hugo Pfoertner, Mar 02 2024

Status

approved