OFFSET
1,1
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..1786
MATHEMATICA
FactorInteger[#][[1, 1]]&/@Select[(2^Range[70]+1), CompositeQ] (* Harvey P. Dale, Feb 17 2017 *)
PROG
(PARI) for(n=1, 1e2, if(!ispseudoprime(2^n+1), p=factor(2^n+1)[1, 1]; print1(p, ", ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
Felix Fröhlich, Aug 11 2014
STATUS
approved