OFFSET
1,2
COMMENTS
8 is in the list because composite(8) + 8 = 15 + 8 = 23 is prime.
27 is in the list because composite(27) + 27 = 40 + 27 = 67 is prime.
MATHEMATICA
nn=400; With[{cnos=Rest[Complement[Range[nn], Prime[Range[PrimePi[nn]]]]]}, Transpose[Select[Thread[{cnos, Range[Length[cnos]]}], PrimeQ[Total[#]]&]][[2]]] (* Harvey P. Dale, Mar 24 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Claudio Meller, Jun 13 2009
STATUS
approved