A107463 a(0)=0, a(n)=1 if n is 1 or is a prime, otherwise sum of prime factors of n with multiplicity.

0, 1, 1, 1, 4, 1, 5, 1, 6, 6, 7, 1, 7, 1, 9, 8, 8, 1, 8, 1, 9, 10, 13, 1, 9, 10, 15, 9, 11, 1, 10, 1, 10, 14, 19, 12, 10, 1, 21, 16, 11, 1, 12, 1, 15, 11, 25, 1, 11, 14, 12, 20, 17, 1, 11, 16, 13, 22, 31, 1, 12, 1, 33, 13, 12, 18, 16, 1, 21, 26, 14, 1, 12, 1, 39, 13, 23, 18, 18, 1, 13, 12

Offset: 0

Author

Giovanni Teofilatto, May 27 2005

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 0..20000

Crossrefs

Cf. A001414.

Programs

Mathematica

Array[If[PrimeQ@ #, 1, Total@ Apply[Times, FactorInteger@ #, 1]] &, 81] (* Michael De Vlieger, Feb 25 2018 *)

PARI

A001414(n) = { my(f=factor(n)); sum(k=1, matsize(f)[1], f[k, 1]*f[k, 2]); }; \\ From A001414.
A107463(n) = if(n<=1,n,if(isprime(n),1,A001414(n))); \\ Antti Karttunen, Feb 25 2018

Extensions

Edited, corrected and extended by Franklin T. Adams-Watters, May 12 2006