OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
MATHEMATICA
spd[n_]:=Total[Select[Divisors[n], PrimeOmega[#]==2&]]; spd/@Select[ Range[ 100], CompositeQ] (* Harvey P. Dale, Nov 25 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Oct 12 2003
STATUS
approved