OFFSET
1,2
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..500
MATHEMATICA
a=0; s=0; Do[s=DivisorSigma[1, EulerPhi[n]]-EulerPhi[DivisorSigma[1, n]]; If[s>a, a=s; Print[s]], {n, 1, 10000}]; (* Output is s. *)
PROG
(PARI) { n=r=0; for (m=1, 10^9, x=sigma(eulerphi(m)) - eulerphi(sigma(m)); if (x > r, r=x; write("b065394.txt", n++, " ", x); if (n==500, return)) ) } \\ Harry J. Smith, Oct 18 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Nov 05 2001
STATUS
approved