OFFSET
1,1
EXAMPLE
a(1) = 6 counts the 6 primes 7, 11, 13, 17, 19 and 23 between 6 and 28.
a(2) = 85 counts the 85 primes 29, 31, ..., 487, 491 between 28 and 496.
MATHEMATICA
PrimePi[Last[#]]-PrimePi[First[#]]&/@(Partition[(# (#+1))/2&/@ Select[ 2^Range[30]-1, PrimeQ], 2, 1]) (* Harvey P. Dale, Dec 27 2011 *)
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Juri-Stepan Gerasimov, Aug 11 2009
EXTENSIONS
Edited by R. J. Mathar, Aug 26 2009
More terms from Harvey P. Dale, Dec 27 2011
a(7) from the data at A185174 added by Amiram Eldar, Sep 03 2024
STATUS
approved