OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
N:= 1001: # to get all a(n) where A006881(n) < N
Primes:= select(isprime, [2, seq(2*k+1, k=1..floor(N/2))]):
L:= sort(convert({seq(seq(p*q, q=Primes[1..ListTools:-BinaryPlace(Primes, N/p)]), p=Primes)} minus {seq(p^2, p=Primes)}, list)):
ListTools:-PartialSums(L); # Robert Israel, Apr 29 2018
MATHEMATICA
f[n_]:=Last/@FactorInteger[n]=={1, 1}; s=0; lst={}; Do[If[f[n], AppendTo[lst, s+=n]], {n, 6!}]; lst
With[{nn=50}, Take[Accumulate[Union[Times@@@Subsets[Prime[Range[nn]], {2}]]], nn]] (* Harvey P. Dale, Aug 08 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Nov 26 2009
STATUS
approved