A123528 Numerator of average of prime factors of n.

2, 3, 2, 5, 5, 7, 2, 3, 7, 11, 7, 13, 9, 4, 2, 17, 8, 19, 3, 5, 13, 23, 9, 5, 15, 3, 11, 29, 10, 31, 2, 7, 19, 6, 5, 37, 21, 8, 11, 41, 4, 43, 5, 11, 25, 47, 11, 7, 4, 10, 17, 53, 11, 8, 13, 11, 31, 59, 3, 61, 33, 13, 2, 9, 16, 67, 7, 13, 14, 71, 12, 73, 39, 13, 23, 9, 6, 79, 13, 3, 43, 83, 7

Offset: 2

Author

Franklin T. Adams-Watters, Oct 02 2006

Keywords

• frac
• nonn

Examples

			12 = 2 * 2 * 3, so a(12) = (2 + 2 + 3) / 3 = 7/3.
Sequence of fractions starts 2/1, 3/1, 2/1, 5/1, 5/2, 7/1, 2/1, 3/1, 7/2, 11/1, 7/3.
		

Links

• G. C. Greubel, Table of n, a(n) for n = 2..5000

Crossrefs

Cf. A123529, A067629, A001414, A001222.

Programs

Mathematica

f[n_] := Plus @@ Times @@@ FactorInteger@n; f[1] = 0; Numerator[ Table[ f[n]/PrimeOmega[n], {n, 2, 50}]] (* G. C. Greubel, Oct 14 2017 *)

Formula

a(n) = sopfr(n) / bigomega(n) = A001414(n) / A001222(n).