OFFSET
1,1
LINKS
Zak Seidov, Table of n, a(n) for n = 1..1000
EXAMPLE
314 = 2*157 and 2 + 157 = 159 =3 * 53 (semiprime).
MATHEMATICA
fQ[n_] := Plus @@ Last /@ FactorInteger@n == 2; Select[ Range@513, fQ@# && fQ[ Plus @@ Flatten[ Table[First@#, {Last@#}] & /@ FactorInteger@# ]] &] (* Robert G. Wilson v *)
Select[Range[600], PrimeOmega[#]==PrimeOmega[Total[Flatten[Table[#[[1]], {#[[2]]}]&/@FactorInteger[#]]]]==2&] (* Harvey P. Dale, Jan 22 2013 *)
PROG
(PARI) list(lim)=my(v=List()); forprime(p=2, sqrt(lim), forprime(q=p, lim\p, if(bigomega(p+q)==2, listput(v, p*q)))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Sep 09 2012
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Mar 09 2006
EXTENSIONS
More terms from Robert G. Wilson v, Apr 12 2006
STATUS
approved