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A065392 a(n) = A062401(A065391(n)): phi(sigma(m)) peak values for m's (listed in A065391) at which those peaks are first reached. 3
1, 2, 6, 8, 12, 30, 36, 72, 126, 180, 360, 432, 660, 930, 1512, 2160, 3300, 3780, 5184, 6552, 11160, 13860, 19800, 23232, 32760, 45360, 47520, 50400, 58080, 61776, 102300, 110160, 137592, 155520, 163296, 196560, 212960, 252000, 272160, 284580 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..100

MATHEMATICA

With[{s = Array[EulerPhi@ DivisorSigma[1, #] &, 10^5]}, Union@ FoldList[Max, s] ] (* Michael De Vlieger, Dec 06 2018 *)

PROG

(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

CROSSREFS

Cf. A000010, A000203, A065391, A065389-A065394.

Sequence in context: A263312 A226818 A113462 * A030457 A296300 A224470

Adjacent sequences:  A065389 A065390 A065391 * A065393 A065394 A065395

KEYWORD

nonn

AUTHOR

Labos Elemer, Nov 14 2001

STATUS

approved

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Last modified October 1 03:28 EDT 2020. Contains 337441 sequences. (Running on oeis4.)