OFFSET
1,3
REFERENCES
David Burton, Elementary Number Theory" 4th edition, problem 7a in section 7.2 has the equivalent of n/phi(n) <= 2*sqrt(n). - Jud McCranie, Aug 30 2004
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..10000
MATHEMATICA
Table[Floor[2*Sqrt[n]*EulerPhi[n]]-n, {n, 1, 100}] (* G. C. Greubel, Jan 14 2019 *)
PROG
(PARI) vector(100, n, (2*sqrt(n)*eulerphi(n))\1 -n) \\ G. C. Greubel, Jan 14 2019
(Magma) [Floor(2*Sqrt(n)*EulerPhi(n)) - n: n in [1..100]]; // G. C. Greubel, Jan 14 2019
(Sage) [floor(2*sqrt(n)*euler_phi(n)) - n for n in (1..100)] # G. C. Greubel, Jan 14 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Aug 30 2004
STATUS
approved