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A130003
a(n) is the smallest positive integer m such that 4^k + m is prime for all k=1,2,...,n.
0
1, 1, 3, 7, 7, 15, 37, 163, 177, 4503, 4503, 4503, 4503, 4503, 833021343, 12465115083, 95854279610863, 1158174141556287
OFFSET
1,3
LINKS
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
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