A095402 Sum of digits of all distinct prime factors of n.

0, 2, 3, 2, 5, 5, 7, 2, 3, 7, 2, 5, 4, 9, 8, 2, 8, 5, 10, 7, 10, 4, 5, 5, 5, 6, 3, 9, 11, 10, 4, 2, 5, 10, 12, 5, 10, 12, 7, 7, 5, 12, 7, 4, 8, 7, 11, 5, 7, 7, 11, 6, 8, 5, 7, 9, 13, 13, 14, 10, 7, 6, 10, 2, 9, 7, 13, 10, 8, 14, 8, 5, 10, 12, 8, 12, 9, 9, 16, 7, 3, 7, 11, 12, 13, 9, 14, 4, 17, 10

Offset: 1

Author

Labos Elemer, Jun 21 2004

Keywords

• nonn
• base

Examples

			n = 1000: prime set = {2, 5}, a[1000] = 7;
n = 255255: prime set={3, 5, 7, 11, 13, 17}, a[255255]= 3+5+7+2+4+8 = 29.
		

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007953, A051351, A141346.

Programs

Mathematica

ffi[x_] :=Flatten[FactorInteger[x]] lf[x_] :=Length[FactorInteger[x]] ba[x_] :=Table[Part[ffi[x], 2*j-1], {j, 1, lf[x]}] sd[x_] :=Apply[Plus, IntegerDigits[x]] tdp[x_] :=Flatten[Table[IntegerDigits[Part[ba[x], j]], {j, 1, lf[x]}], 1] sdp[x_] :=Apply[Plus, tdp[x]] Table[sdp[w], {w, 1, 150}]
Table[Total[Flatten[IntegerDigits[First/@FactorInteger[n]]]],{n,1,100}] (Zak Seidov)

Python

from sympy import factorint
def a(n): return sum(sum(map(int, str(p))) for p in factorint(n))
print([a(n) for n in range(1, 91)]) # Michael S. Branicky, Dec 12 2023