A130003 a(n) is the smallest positive integer m such that 4^k + m is prime for all k=1,2,...,n.

1, 1, 3, 7, 7, 15, 37, 163, 177, 4503, 4503, 4503, 4503, 4503, 833021343, 12465115083, 95854279610863, 1158174141556287

Offset

1,3

Links

Table of n, a(n) for n=1..18.

Carlos Rivera, Puzzle 403. 833021343, The Prime Puzzles and Problems Connection.

Example

a(14)=4503 because 4^k + 4503 is prime for each k in 1..14 and there is no smaller number with this property.

Crossrefs

Cf. A110096.

Sequence in context: A175329 A081218 A240422 * A098581 A238997 A240260

Adjacent sequences: A130000 A130001 A130002 * A130004 A130005 A130006

Keyword

nonn,hard,more

Author

Farideh Firoozbakht, May 30 2007, Jun 04 2007

Extensions

More terms from Jens Kruse Andersen, Jun 08 2007

Status

approved