A285183 - OEIS

A285183

Nearest integer to n*omega(n)/phi(n).

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

1,2

COMMENTS

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

REFERENCES

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.

LINKS

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

Paul 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