OFFSET
1,2
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..500
EXAMPLE
A062402 begins {1, 1, 3, 3, 7, 3, 12, 7, 12, 7, 18, 7, 28, 12, 15, 15, 31, 12, 39, 15, 28, 18, 36, 15, 42}. New peaks are reached at positions 3, 5, 7, 11, 13, 17, 19, 25. These peak values are 3, 7, 12, 18, 28, 31, 39, 42 respectively.
MATHEMATICA
a=0; s=0; Do[s=DivisorSigma[1, EulerPhi[n]]; If[s>a, a=s; Print[n]], {n, 1, 10000}];
DeleteDuplicates[Table[{n, DivisorSigma[1, EulerPhi[n]]}, {n, 2600}], GreaterEqual[#1[[2]], #2[[2]]]&][[;; , 1]] (* Harvey P. Dale, Jul 20 2023 *)
PROG
(PARI) { n=r=0; for (m=1, 10^9, x=sigma(eulerphi(m)); if (x > r, r=x; write("b065389.txt", n++, " ", m); if (n==500, return)) ) } \\ Harry J. Smith, Oct 18 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Nov 05 2001
STATUS
approved