S000932


Number of distinct prime factors in the n-th primitive abundant number (A006038).

3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 4, 4, 4, 5, 4, 5, 4, 4, 5, 4, 5, 4, 5, 4, 4, 4, 4, 5, 4, 4, 4, 5, 5, 4, 5, 5, 5, 5, 5, 4, 5, 4, 4, 5, 5, 4, 4, 5, 5, 5, 4, 5, 4, 5, 5, 5, 4, 5, 4, 5, 4, 5, 4, 5, 3, 5, 4, 5, 5, 5, 4, 5, 4

1

S000932

There are 8 threes and 576 fours.

T. D. Noe, Plot of 10000 terms

T. D. Noe, Table of 10000 terms

Wikipedia, Primitive abundant number

(Mma) t = {}; tf = {}; tds = {}; n = 1; While[Length[t] < 100, n = n + 2; ds = DivisorSigma[1, n]; If[ds > 2 n && Intersection[t, Divisors[n]] == {}, AppendTo[t, n]; AppendTo[tf, Length[FactorInteger[n]]]; AppendTo[tds, ds/n]]]; tf

Cf. A006038, A188439.

nonn

T. D. Noe, Jul 31 2016

© Tony D Noe 2014-2016