OFFSET
1,1
COMMENTS
No more primes up to 21st recurrence step. - Artur Jasinski, Sep 20 2008
Andersen's page shows that A000058(30) is the first number whose primality is unknown. Thus if a(6) exists it has over 218 million decimal digits.
LINKS
Jens Kruse Andersen, Factorization of Sylvester's sequence
Eric Weisstein's World of Mathematics, Sylvester's Sequence
MATHEMATICA
a = {}; k = 2; Do[k = k^2 - k + 1; If[PrimeQ[k], AppendTo[a, k]], {n, 1, 15}]; a (* Artur Jasinski, Sep 20 2008 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved