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#18 by Bruno Berselli at Wed May 10 05:30:49 EDT 2017
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#17 by Indranil Ghosh at Wed May 10 03:26:05 EDT 2017
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#16 by Indranil Ghosh at Wed May 10 03:25:57 EDT 2017
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| PROG
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def P(n):
f = factorint(n)
def P(n): return sorted([factorint(n)[f[i] for i in factorint(n)])f])
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| STATUS
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approved
editing
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#15 by Michel Marcus at Sat May 06 03:41:38 EDT 2017
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#14 by Joerg Arndt at Sat May 06 03:38:43 EDT 2017
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#13 by Indranil Ghosh at Sat May 06 03:06:12 EDT 2017
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#12 by Indranil Ghosh at Sat May 06 03:05:32 EDT 2017
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| PROG
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(Python)
from sympy import factorint, totient
def T(n, m): return ((n + m)**2 - n - 3*m + 2)/2
def P(n): return sorted([factorint(n)[i] for i in factorint(n)])
def a046523(n):
x=1
while True:
if P(n) == P(x): return x
else: x+=1
def a(n): return T(totient(n), a046523(n)) # Indranil Ghosh, May 06 2017
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| STATUS
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approved
editing
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#11 by N. J. A. Sloane at Thu May 04 09:39:41 EDT 2017
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#10 by Antti Karttunen at Thu May 04 09:39:18 EDT 2017
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#9 by Antti Karttunen at Thu May 04 09:37:25 EDT 2017
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| CROSSREFS
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Cf. alsofor example A061468. (one of the sequences this matches with).
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Discussion
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| Thu May 04
| 09:39
| Antti Karttunen: Used as a filtering sequence, thus longish data section.
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