OFFSET
1,1
COMMENTS
A072762(4211) tested as PRP, others certified primes.
A072762(4211) is prime. a(8) > 200000. - Jason Yuen, Oct 26 2024
EXAMPLE
MATHEMATICA
F[j_] := PrimeQ[Numerator[ Sum[ 1/2^Prime[k], {k, 1, j} ] ]] ; Prime[Select[Range[600], F]]
CROSSREFS
KEYWORD
hard,nonn,more,base,changed
AUTHOR
Anton Vrba (antonvrba(AT)yahoo.com), Nov 24 2006
STATUS
approved