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A107463
a(0)=0, a(n)=1 if n is 1 or is a prime, otherwise sum of prime factors of n with multiplicity.
3
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
0,5
LINKS
MATHEMATICA
Array[If[PrimeQ@ #, 1, Total@ Apply[Times, FactorInteger@ #, 1]] &, 81] (* Michael De Vlieger, Feb 25 2018 *)
PROG
(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
CROSSREFS
Cf. A001414.
Sequence in context: A339967 A357311 A373364 * A157104 A101322 A029644
KEYWORD
nonn
AUTHOR
Giovanni Teofilatto, May 27 2005
EXTENSIONS
Edited, corrected and extended by Franklin T. Adams-Watters, May 12 2006
STATUS
approved