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A096865 Function A062401(x) = phi(sigma(x)) is iterated. Starting with n, a(n) is the smallest term arising in trajectory, either in transient or in terminal cycle. 7
1, 2, 2, 4, 2, 4, 4, 8, 9, 4, 4, 12, 4, 8, 8, 16, 4, 16, 8, 12, 16, 12, 8, 16, 16, 12, 16, 16, 8, 16, 16, 32, 16, 16, 16, 36, 16, 16, 16, 16, 12, 32, 12, 16, 16, 16, 16, 48, 36, 48, 16, 32, 16, 32, 16, 32, 32, 16, 16, 48, 16, 32, 48, 64, 16, 48, 32, 36, 32, 48, 16, 72, 36, 36, 48 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..16384

EXAMPLE

n=255: list={255,144,360,288,[432,480],432,...}, a(255)=144 as a transient term;

n=254: list={254,[128],128,...}, a(254)=128, as a fixed point.

MATHEMATICA

fs[x_] :=EulerPhi[DivisorSigma[1, x]] itef[x_, hos_] :=NestList[fs, x, hos] Table[Min[itef[w, 20]], {w, 1, 256}]

PROG

(Scheme) (define (A096865 n) (let loop ((visited (list n)) (m n)) (let ((next (A062401 (car visited)))) (cond ((member next visited) m) (else (loop (cons next visited) (min m next))))))) ;; Antti Karttunen, Nov 18 2017

CROSSREFS

Cf. A062401, A062402, A095955, A096859, A096860, A096861 (largest term).

Cf. also A096866.

Sequence in context: A001316 A285741 A161831 * A116466 A116467 A079314

Adjacent sequences:  A096862 A096863 A096864 * A096866 A096867 A096868

KEYWORD

nonn

AUTHOR

Labos Elemer, Jul 21 2004

STATUS

approved

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Last modified December 5 06:51 EST 2020. Contains 338944 sequences. (Running on oeis4.)