A246839 Number of trailing zeros in A002109(n).
0, 0, 0, 0, 0, 5, 5, 5, 5, 5, 15, 15, 15, 15, 15, 30, 30, 30, 30, 30, 50, 50, 50, 50, 50, 100, 100, 100, 100, 100, 130, 130, 130, 130, 130, 165, 165, 165, 165, 165, 205, 205, 205, 205, 205, 250, 250, 250, 250, 250, 350, 350, 350, 350, 350, 405, 405, 405, 405
Offset: 0
Links
- Chai Wah Wu, Table of n, a(n) for n = 0..999
Programs
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Mathematica
(n=#;k=0;While[Mod[n,10]==0,n=n/10;k++];k)&/@Hyperfactorial@Range[0,60] (* Giorgos Kalogeropoulos, Sep 14 2021 *)
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PARI
a(n) = sum(i=1, n, i*valuation(i, 5)); \\ Michel Marcus, Sep 14 2021
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Python
def a(n): s = 1 for k in range(n+1): s *= k**k i = 1 while not s % 10**i: i += 1 return i-1 n = 1 while n < 100: print(a(n),end=', ') n += 1 # Derek Orr, Sep 04 2014 -
Python
from sympy import multiplicity A246839, p5 = [0,0,0,0,0], 0 for n in range(5,10**3,5): p5 += multiplicity(5,n)*n A246839.extend([p5]*5) # Chai Wah Wu, Sep 05 2014