OFFSET
1,1
COMMENTS
See A377120 for a guide to related sequences.
EXAMPLE
prime(3) = 5 -> 7 -> 11 -> 19 -> 35 = 5*7, so a(1) = 4.
MATHEMATICA
Table[p = Prime[n]; c = 1; While[p = 2*p + 7; PrimeQ[p], c++]; c, {n, 200}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Nov 05 2024
STATUS
approved