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

1,2

Links

Table of n, a(n) for n=1..60.

Neville Holmes, Integer Sequence Combinations

Example

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

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 *)

Crossrefs

Applies A000096 to A001414. Cf. A074373, A074374.

Sequence in context: A314925 A314926 A314927 * A314928 A314929 A314930

Adjacent sequences: A074372 A074373 A074374 * A074376 A074377 A074378

Keyword

easy,nonn

Author

W. Neville Holmes, Aug 29 2002

Status

approved