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A285183
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Nearest integer to n*omega(n)/phi(n).
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2
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0, 2, 2, 2, 1, 6, 1, 2, 2, 5, 1, 6, 1, 5, 4, 2, 1, 6, 1, 5, 4, 4, 1, 6, 1, 4, 2, 5, 1, 11, 1, 2, 3, 4, 3, 6, 1, 4, 3, 5, 1, 11, 1, 4, 4, 4, 1, 6, 1, 5, 3, 4, 1, 6, 3, 5, 3, 4, 1, 11, 1, 4, 4, 2, 3, 10, 1, 4, 3, 9, 1, 6, 1, 4, 4, 4, 3, 10, 1, 5, 2, 4, 1, 11, 3, 4, 3, 4, 1, 11, 3, 4, 3, 4, 3, 6
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OFFSET
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1,2
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COMMENTS
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n*omega(n)/phi(n) appears in certain bounds of Erdős for the Jacobsthal function g(n) (A048669).
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REFERENCES
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József Sándor, Dragoslav S. Mitrinovic, and Borislav Crstici, Handbook of Number Theory I, Springer Science & Business Media, 2005, Chapter I, p. 34, section I.32.3.
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LINKS
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MAPLE
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Digits:=30;
A001221 := proc(n) nops(numtheory[factorset](n)) end proc:
with(numtheory);
t1:=[seq(f(n), n=1..130)];
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MATHEMATICA
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PROG
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(Magma) [Round(n*#PrimeDivisors(n)/EulerPhi(n)): n in [1..100]] // Vincenzo Librandi, Apr 21 2017
(PARI) a(n) = {my(f = factor(n)); round(n*omega(f)/eulerphi(f)); } \\ Amiram Eldar, Apr 25 2024
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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