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A285183 Nearest integer to n*omega(n)/phi(n). 2
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

n*omega(n)/phi(n) appears in certain bounds of Erdos for the Jacobsthal function g(n) (A048669).

REFERENCES

D. S. Mitrinovic et al., Handbook of Number Theory, Kluwer, Pages 33-34.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

P. Erdős, On the integers relatively prime to n and on a number theoretic function considered by Jacobsthal, Math. Scand., 10, 1962, 163-170.

MAPLE

Digits:=30;

A001221 := proc(n) nops(numtheory[factorset](n)) end proc:

with(numtheory);

f:=n->round(n*A001221(n)/phi(n));

t1:=[seq(f(n), n=1..130)];

MATHEMATICA

Round[Table[(n PrimeNu[n] + 1/2)/EulerPhi[n], {n, 1, 100}]] (* Vincenzo Librandi, Apr 21 2017 - confirmed by Giovanni Resta *)

PROG

(MAGMA) [Round(n*#PrimeDivisors(n)/EulerPhi(n)): n in [1..100]] // Vincenzo Librandi, Apr 21 2017

CROSSREFS

Cf. A000010 (phi), A001221 (omega), A048669.

Sequence in context: A109978 A114293 A295691 * A255399 A181830 A086612

Adjacent sequences:  A285180 A285181 A285182 * A285184 A285185 A285186

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Apr 19 2017

STATUS

approved

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Last modified August 4 13:36 EDT 2020. Contains 336201 sequences. (Running on oeis4.)