A096859 -id:A096859 - cp's OEIS frontend

A096860 Function A062401(x) = phi(sigma(x)) = f(x) is iterated. Starting with n, a(n) is the count of distinct terms arising in the transient of this trajectory, that is: a(n) = A096859(n) - A095955(n).

0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 2, 1, 2, 1, 1, 2, 1, 1, 1, 1, 3, 2, 1, 1, 1, 1, 0, 2, 1, 1, 4, 2, 3, 1, 3, 3, 1, 1, 0, 1, 3, 1, 2, 1, 1, 3, 2, 3, 1, 1, 0, 2, 2, 1, 1, 3, 1, 3, 1, 2, 2, 1, 1, 2, 2, 3, 1, 1, 1, 1, 1, 3, 1, 3, 0, 4, 2, 1, 5, 3, 1, 1, 1, 3

Offset: 1

Labos Elemer, Jul 21 2004

nonn

			n=255: list={255,144,360,288,[432,480],432,...}, t=transient=4, c=cycle=2, a(255)=t=4;
n=244: list={244,180,144,360,288,[432,480],432,...}, a(244)=4.
a(n)=0 means that n is a recurrent term from A096850.

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

Cf. A000010, A000203, A062401, A062402, A095955, A096859, A096861, A096865.

Cf. also A096863.

With[{nn = 120}, Array[Length@ Union@ # - Length@ Select[Tally@ #, Last@ # > 1 &] &@ NestList[EulerPhi@ DivisorSigma[1, #] &, #, nn] &, 105]] (* Michael De Vlieger, Nov 18 2017 *)

(define (A096860 n) (let loop ((visited (list n))) (let ((next (A062401 (car visited)))) (cond ((member next visited) => (lambda (transientplusone) (- (length transientplusone) 1))) (else (loop (cons next visited))))))) ;; Antti Karttunen, Nov 18 2017

A097007 a(n) = index of first appearance of n in A096859.

Original entry on oeis.org

1, 3, 7, 18, 34, 52, 100, 422, 882, 1008, 960, 912, 784, 1497, 3187, 13456, 21336, 42682, 69696, 50176, 73191, 112896, 88452, 151828, 140736, 198876, 245028, 187272, 252964, 207936, 229456, 447201, 1412589, 9734400, 7757136, 7910076

Offset: 1

Labos Elemer, Jul 26 2004

nonn

a(n) = smallest k such that A096860(k) + A095955(k) = n.

a(n) = smallest k such that n equals the index of the term that completes the first cycle in the trajectory of k under iteration of f(x) = A062401(x) = phi(sigma(x)).

			The trajectory of 18 under iteration of f(x) is 18, 24, 16, 30, 24, 16, 30, ...; the cycle (24, 16, 30) is completed at the fourth term and for j < 18 the first cycle in trajectory of j under iteration of f(x) is completed at the first, second or third term, hence a(4) = 18.
The trajectory of 69696 under iteration of f(x) is 69696, 163296, 157248, 193536, 247808, 217728, 147456, 324000, 285120, 332640, 331776, 900900, 967680, 991232, 1143072, 2122848, 2201472, 1658880, 1801800, 1658880, 1801800, ...; the cycle (1658880, 1801800) is completed at the 19th term and for j < 69696 the first cycle in trajectory
of j under iteration of f(x) is completed at an earlier term, hence a(19) = 69696.

Klaus Brockhaus, Table of n, a(n) for n=1..119

Cf. A062401, A096859, A096860, A095955, A097008.

fs[x_] :=EulerPhi[DivisorSigma[1, x]]; nsf[x_, ho_] :=NestList[fs, x, ho]; luf[x_, ho_] :=Length[Union[nsf[x, ho]]] t=Table[0, {35}]; Do[s=luf[n, 100]; If[s<36&&t[[s]]==0, t[[s]]=n], {n, 1, 1600000}]; t

{v=vector(40); for(n=1, 10000000, k=n; s=Set(k); until(setsearch(s, k=eulerphi(sigma(k))), s=setunion(s, Set(k))); a=#s; if(a<=m&&v[a]==0, v[a]=n)); v} /* Klaus Brockhaus, Jul 16 2007 */

Edited, a(27) corrected and a(34) through a(36) added by Klaus Brockhaus, Jul 16 2007

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.

Original entry on oeis.org

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

Offset: 1

Labos Elemer, Jul 21 2004

nonn

			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.

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

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

Cf. also A096866.

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

(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

A096861 Function A062401(x) = phi(sigma(x)) = f(x) is iterated. Starting with n, a(n) is the largest term arising in trajectory.

Original entry on oeis.org

1, 2, 3, 6, 5, 6, 7, 8, 12, 10, 11, 12, 13, 14, 15, 30, 17, 30, 19, 20, 30, 22, 23, 30, 30, 26, 30, 30, 29, 30, 31, 96, 33, 34, 35, 96, 37, 38, 39, 40, 41, 96, 43, 44, 45, 46, 47, 60, 96, 60, 51, 96, 53, 96, 55, 96, 96, 58, 59, 60, 61, 96, 63, 126, 65, 66, 96, 96, 96, 70, 71, 96

Offset: 1

Labos Elemer, Jul 21 2004

nonn

			n=255: list={255,144,360,288,[432,480],432,...}, a(255)=480, a recurrent term;
n=247: list={247,96,72,96,...}, a(247)=247, a transient term, here the initial value.

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

Cf. A000010, A000203, A062401, A062402, A095955, A096859, A096865.

Cf. also A096864.

gf[x_] :=DivisorSigma[1, EulerPhi[x]] itef[x_, len_] :=NestList[fs, x, len] Table[Max[itef[w, 20]], {w, 1, 256}]

(define (A096861 n) (let loop ((visited (list n)) (m n)) (let ((next (A062401 (car visited)))) (cond ((member next visited) m) (else (loop (cons next visited) (max m next))))))) ;; Antti Karttunen, Nov 18 2017

A096862 Function A062402(x)=sigma(phi(x)) is iterated. Starting with n, a(n) is the count of distinct terms arising during this trajectory; a(n)=t(n)+c(n)=t+c, where t is the number of transient terms, c is the number of recurrent terms [in the terminal cycle].

Original entry on oeis.org

1, 2, 1, 2, 3, 2, 2, 3, 3, 3, 4, 2, 2, 3, 1, 2, 4, 3, 5, 2, 2, 4, 3, 2, 3, 2, 5, 1, 5, 2, 3, 4, 3, 4, 4, 2, 4, 5, 4, 4, 5, 2, 6, 3, 4, 3, 4, 4, 6, 3, 5, 4, 7, 5, 5, 4, 4, 5, 5, 3, 3, 4, 4, 5, 3, 3, 4, 5, 5, 4, 4, 3, 3, 4, 5, 4, 3, 4, 3, 5, 6, 5, 5, 4, 5, 6, 6, 5, 4, 4, 3, 5, 3, 4, 3, 5, 3, 6, 3, 5, 8, 5, 4, 3, 3

Offset: 1

Labos Elemer, Jul 21 2004

nonn

			n=256: list={256,255,255}, transient=t=1, cycle=c=1, a(256)=t+c=2.

Cf. A062401, A062402, A095955, A096859-A096866.

gf[x_] :=DivisorSigma[1, EulerPhi[x]] gite[x_, hos_] :=NestList[gf, x, hos] Table[Length[Union[gite[w, 1000]]], {w, 1, 256}]

A096863 Function A062402(x)=sigma(phi(x)) is iterated. Starting with n, a(n) is the count of transient terms of trajectory.

Original entry on oeis.org

0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 2, 0, 1, 1, 0, 1, 1, 1, 2, 1, 1, 2, 2, 1, 2, 1, 2, 0, 2, 1, 0, 1, 2, 1, 1, 1, 2, 2, 1, 1, 2, 1, 4, 2, 1, 2, 1, 1, 4, 2, 3, 1, 5, 2, 2, 1, 2, 2, 2, 0, 1, 1, 2, 3, 1, 2, 2, 3, 2, 1, 2, 0, 1, 2, 2, 2, 1, 1, 1, 3, 4, 2, 3, 1, 3, 4, 4, 2, 2, 1, 1, 2, 1, 1, 1, 3, 1, 4, 1, 2, 6, 3, 2, 1, 1

Offset: 1

Labos Elemer, Jul 21 2004

nonn

a(n)=0 means that n is a recurrent term from A096998.

			n=256: list={256,255,255}, a(256)=1;
n=101: list={101,217,546,403,1170,819,[1240,1512],1240,...,a(101)=6;

Cf. A062401, A062402, A095955, A096859-A096866, A096993.

a(n) = A096861(n)-A096993(n).

A097005 A062401(x) is iterated. Initial value = n!. a(n) is the path-length of trajectory = count of transients and recurrent terms, i.e., all distinct states arising in trajectory.

Original entry on oeis.org

1, 1, 1, 2, 3, 3, 1, 9, 6, 14, 2, 51, 35, 81, 32, 31

Offset: 0

Labos Elemer, Jul 22 2004

			n=10: 10! = 3628800; trajectory ={3628800, 5702400, 5702400, ...} a(10) = 2, one transient and 1 cycle term.

Cf. A000010, A000142, A000203, A062401, A096859.

fs[x_]:=EulerPhi[DivisorSigma[1,x]] itef[x_,len_]:=NestList[fs,x,len] Table[Length[Union[itef[w!,1000]]],{w,0,16}]

a(n) = A096859(n!) = A096859(A000142(n)). - Michel Marcus, Jul 27 2017

cp's OEIS Frontend

A096860 Function A062401(x) = phi(sigma(x)) = f(x) is iterated. Starting with n, a(n) is the count of distinct terms arising in the transient of this trajectory, that is: a(n) = A096859(n) - A095955(n).

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A097007 a(n) = index of first appearance of n in A096859.

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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.

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A096861 Function A062401(x) = phi(sigma(x)) = f(x) is iterated. Starting with n, a(n) is the largest term arising in trajectory.

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A096862 Function A062402(x)=sigma(phi(x)) is iterated. Starting with n, a(n) is the count of distinct terms arising during this trajectory; a(n)=t(n)+c(n)=t+c, where t is the number of transient terms, c is the number of recurrent terms [in the terminal cycle].

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A096863 Function A062402(x)=sigma(phi(x)) is iterated. Starting with n, a(n) is the count of transient terms of trajectory.

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A097005 A062401(x) is iterated. Initial value = n!. a(n) is the path-length of trajectory = count of transients and recurrent terms, i.e., all distinct states arising in trajectory.

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