A090875 a(n) is the smallest number m such that m^(2^k) + 2^(2^k) is prime for k=0,1,...,n.

1, 1, 1, 1, 1, 2321204055, 37185086099807

Offset

0,6

Comments

The first five terms of this sequence correspond to Fermat primes.

According to the answers to Prime Puzzle 399 (see link), a(6) is larger than 2.3*10^12. - M. F. Hasler, Aug 02 2007

Links

Table of n, a(n) for n=0..6.

Carlos Rivera (ed.), Puzzle 399. Some more terms, The Prime Puzzles and Problems Connection.

Example

a(5)=2321204055 because 2321204055 is the smallest number m such that m^(2^k) + 2^(2^k) is prime for k=0,1,2,3,4 and 5.

Crossrefs

Cf. A090872, A090873, A090874.

Sequence in context: A251490 A277720 A333664 * A132907 A038685 A017289

Adjacent sequences: A090872 A090873 A090874 * A090876 A090877 A090878

Keyword

nonn

Author

Farideh Firoozbakht, Feb 06 2004

Extensions

a(6) found by Kellen Shenton sent in by Jeppe Stig Nielsen, Apr 06 2022

Status

approved