OFFSET
1,1
COMMENTS
Squares of primes are not included. - Zak Seidov, Sep 14 2018
LINKS
Zak Seidov, Table of n, a(n) for n = 1..1000
EXAMPLE
21 = 3*7 and 3 + 7 = 10 = 2*5.
MATHEMATICA
Select[Range[800], Plus@@Last/@FactorInteger[ # ]==Plus@@Last/@FactorInteger[(Plus@@First/@FactorInteger[ # ])]==2&]
PROG
(PARI) is(n) = if(bigomega(n)!=2, return(0), my(f=factor(n)[, 1]~); #f==2 && bigomega(sum(i=1, #f, f[i]))==2) \\ Felix Fröhlich, Sep 17 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Jun 14 2005
EXTENSIONS
Name clarified by David A. Corneth, Sep 17 2018
STATUS
approved