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%I #19 Dec 07 2018 07:54:17
%S 1,2,6,8,12,30,36,72,126,180,360,432,660,930,1512,2160,3300,3780,5184,
%T 6552,11160,13860,19800,23232,32760,45360,47520,50400,58080,61776,
%U 102300,110160,137592,155520,163296,196560,212960,252000,272160,284580
%N a(n) = A062401(A065391(n)): phi(sigma(m)) peak values for m's (listed in A065391) at which those peaks are first reached.
%H Harry J. Smith, <a href="/A065392/b065392.txt">Table of n, a(n) for n = 1..100</a>
%t With[{s = Array[EulerPhi@ DivisorSigma[1, #] &, 10^5]}, Union@ FoldList[Max, s] ] (* _Michael De Vlieger_, Dec 06 2018 *)
%o (PARI) { n=r=0; for (m=1, 10^9, x=eulerphi(sigma(m)); if (x > r, r=x; write("b065392.txt", n++, " ", x); if (n==100, return)) ) } \\ _Harry J. Smith_, Oct 18 2009
%Y Cf. A000010, A000203, A065391, A065389-A065394.
%K nonn
%O 1,2
%A _Labos Elemer_, Nov 14 2001