OFFSET
1,2
EXAMPLE
If n=9, then (p(9)-2*(9-1))/7=(23-16)/7=1=a(1).
If n=75, then (p(75)-2*(75-1))/7=(379-148)/7=33=a(2).
If n=79, then (p(79)-2*(79-1))/7=(401-156)/7=35=a(3).
If n=86, then (p(86)-2*(86-1))/7=(443-170)/7=39=a(4).
If n=90, then (p(90)-2*(90-1))/7=(463-178)/7=49=a(5).
If n=143, then (p(143)-2*(143-1))/7=(823-284)/7=77=a(6), etc.
MATHEMATICA
Select[(Last[#]-2(First[#]-1))/7&/@Table[{n, Prime[n]}, {n, 800}], IntegerQ[#] && !PrimeQ[#]&] (* Harvey P. Dale, Sep 14 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Oct 08 2008
EXTENSIONS
More terms from R. J. Mathar, Apr 13 2010
STATUS
approved