OFFSET
2,2
COMMENTS
Here 0.d means the decimal fraction obtained by writing d after the decimal point, e.g., 0.11 = 11/100.
The first few values of Sum_{p|n} 0.d are: 1/5, 3/10, 1/5, 1/2, 1/2, 7/10, 1/5, 3/10, 7/10, ...
See A276655 - numbers n such that Sum_{p|n} 0.d is an integer.
LINKS
Jaroslav Krizek, Table of n, a(n) for n = 2..1000
FORMULA
a(n) = (Sum_{p|n} 0.d) * A276652(n) where p = prime divisors of n.
EXAMPLE
For n=12; Sum_{p|12} 0.d = 0.2 + 0.3 = 0.5 = 5/10 = 1/2; a(12) = 1.
MATHEMATICA
Numerator[Table[f = FactorInteger[i][[All, 1]];
Total[f*10^-IntegerLength[f]], {i, 2, 76}]] (* Robert Price, Sep 20 2019 *)
PROG
(Magma) [Numerator(&+[d/(10^(#Intseq(d))): d in PrimeDivisors(n)]): n in [2..1000]]
CROSSREFS
KEYWORD
nonn,base,frac
AUTHOR
Jaroslav Krizek, Sep 10 2016
STATUS
approved