OFFSET
1,1
COMMENTS
This is the semiprime analog of A061067.
LINKS
Eric Weisstein, World of Mathematics, Semiprime.
EXAMPLE
a(1) = 10 because 10 = semiprime(4) and semiprime(4) + 4 = 14 is
semiprime.
a(2) = 15 because 15 = semiprime(6) and semiprime(6) + 6 = 21 is
semiprime.
MATHEMATICA
Module[{sp=Select[Range[1000], PrimeOmega[#]==2&], len}, len=Length[sp]; Select[ Thread[{sp, Range[len]}], PrimeOmega[Total[#]]==2&]][[All, 1]] (* Harvey P. Dale, Jan 13 2019 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Ray Chandler, Nov 26 2004
STATUS
approved