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#13 by Michael De Vlieger at Tue Jul 23 10:51:15 EDT 2024
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#12 by Michel Marcus at Tue Jul 23 04:07:50 EDT 2024
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#11 by Chai Wah Wu at Mon Jul 22 17:33:27 EDT 2024
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#10 by Chai Wah Wu at Mon Jul 22 17:33:22 EDT 2024
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| PROG
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return prod((p**(e+1)-1)//(p-1)-1 for p, e in factorint(m).items())-m # Chai Wah Wu, Jul 22 2024
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#9 by Chai Wah Wu at Mon Jul 22 17:33:13 EDT 2024
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(Python)
from math import prod, isqrt
from sympy import mobius, factorint
def A373058(n):
def f(x): return n+sum(mobius(k)*(x//k**2) for k in range(1, isqrt(x)+1))
m, k = n, f(n)
while m != k:
m, k = k, f(k)
return prod((p**(e+1)-1)//(p-1)-1 for p, e in factorint(m).items())-m # Chai Wah Wu, Jul 22 2024
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| STATUS
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approved
editing
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#8 by OEIS Server at Tue May 21 05:27:40 EDT 2024
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| LINKS
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Amiram Eldar, <a href="/A373058/b373058_1.txt">Table of n, a(n) for n = 1..10000</a>
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#7 by Peter Luschny at Tue May 21 05:27:40 EDT 2024
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Discussion
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| Tue May 21
| 05:27
| OEIS Server: Installed first b-file as b373058.txt.
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#6 by Joerg Arndt at Tue May 21 01:14:57 EDT 2024
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#5 by Amiram Eldar at Tue May 21 00:51:29 EDT 2024
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#4 by Amiram Eldar at Tue May 21 00:49:18 EDT 2024
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