OFFSET
1,1
EXAMPLE
43 is in the sequence because it is prime, and 43 = 6^2 + 6 + 1 where 6 = 2*3 is semiprime.
MATHEMATICA
Select[#^2+#+1&/@Select[Range[1000], PrimeOmega[#]==2&], PrimeQ] (* Harvey P. Dale, Jan 06 2013 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jonathan Vos Post, Dec 19 2012
STATUS
approved