A074375 s(s+3)/2 where s is the sum of the prime factors of n (with repetition).

0, 5, 9, 14, 20, 20, 35, 27, 27, 35, 77, 35, 104, 54, 44, 44, 170, 44, 209, 54, 65, 104, 299, 54, 65, 135, 54, 77, 464, 65, 527, 65, 119, 209, 90, 65, 740, 252, 152, 77, 902, 90, 989, 135, 77, 350, 1175, 77, 119, 90, 230, 170, 1484, 77, 152, 104, 275, 527, 1829, 90

Offset: 1

Author

W. Neville Holmes, Aug 29 2002

Keywords

• easy
• nonn

Examples

			a(20) = 9(9+3)/2 = 54 because 9 = 2+2+5 and 20 = 2*2*5.
		

Links

• Neville Holmes, Integer Sequence Combinations

Crossrefs

Applies A000096 to A001414. Cf. A074373, A074374.

Programs

Mathematica

spf[n_]:=Module[{c=Total[Times@@@FactorInteger[n]]},(c(c+3))/2]; Join[ {0}, Rest[Array[spf,60]]] (* Harvey P. Dale, Aug 16 2011 *)