OFFSET
1,1
EXAMPLE
a(1)= 4+2(prime)=6 (composite). a(2)= 4+5(prime)=9 (composite). a(3)=4+11(prime) = 15 (composite).
MATHEMATICA
Select[4+Prime[Range[100]], CompositeQ] (* Harvey P. Dale, Oct 24 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Aug 14 2009
EXTENSIONS
Edited, entries checked, by R. J. Mathar, Aug 20 2009
STATUS
approved