OFFSET
1,1
COMMENTS
Subsequence of A091300. - Zak Seidov, Dec 28 2015
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = 6 * A112775(n) +1.
MATHEMATICA
Select[6 Range[0, 200] + 1, PrimeOmega[#] == 2&] (* Vincenzo Librandi, Sep 22 2012 *)
PROG
(Magma) IsSemiprime:=func<n | &+[d[2]: d in Factorization(n)] eq 2>; [s: n in [2..150] | IsSemiprime(s) where s is 6*n + 1]; // Vincenzo Librandi, Sep 22 2012
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post and Ray Chandler, Oct 15 2005
STATUS
approved