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A134599
Sum of digital sums (base 3) of the prime factors of n.
19
2, 1, 4, 3, 3, 3, 6, 2, 5, 3, 5, 3, 5, 4, 8, 5, 4, 3, 7, 4, 5, 5, 7, 6, 5, 3, 7, 3, 6, 3, 10, 4, 7, 6, 6, 3, 5, 4, 9, 5, 6, 5, 7, 5, 7, 5, 9, 6, 8, 6, 7, 7, 5, 6, 9, 4, 5, 5, 8, 5, 5, 5, 12, 6, 6, 5, 9, 6, 8, 7, 8, 5, 5, 7, 7, 6, 6, 7, 11, 4, 7, 3, 8, 8, 7, 4, 9, 5, 7, 6, 9, 4, 7, 6, 11, 5, 8, 5, 10, 5, 8, 5, 9, 7
OFFSET
2,1
FORMULA
If p_1*p_2*p_3* ... *p_m=n is the unique prime factorization of n, then a(n)=sum{1<=k<=m, ds_3(p_k)}, where ds_3 is the digital sum base 3.
EXAMPLE
a(6)=3, since 6=2*3 and so a(6)=ds_3(2)+ds_3(3)=2+1.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Hieronymus Fischer, Nov 11 2007
STATUS
approved