Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #5 Jul 13 2019 09:13:27
%S 1,2,1,3,3,4,1,2,2,5,4,6,5,5,1,7,5,8,5,3,3,9,5,3,7,2,2,10,2,11,1,7,4,
%T 7,3,12,9,4,3,13,7,14,7,7,5,15,6,4,7,9,8,16,7,4,7,5,11,17,7,18,6,8,1,
%U 9,8,19,3,11,8,20,7,21,13,8,10,9,3,22,7,2,7
%N Numerator of the average of the multiset of prime indices of n.
%C A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.
%e The prime indices of 12 are {1,1,2}, with average 4/3, so a(12) = 4.
%t Table[Numerator[Sum[q[[2]]*PrimePi[q[[1]]],{q,FactorInteger[n]}]/PrimeOmega[n]],{n,2,100}]
%Y Cf. A001222, A001414, A056239, A067629, A112798, A123528/A123529, A289508, A289509, A290103, A316413, A326568.
%K nonn,frac
%O 2,2
%A _Gus Wiseman_, Jul 13 2019