|
| |
|
|
A096852
|
|
a(n) is the length of terminal cycle of the trajectory of f(x)=phi(sigma(x)) if started at 2^n.
|
|
10
| |
|
|
1, 1, 2, 1, 3, 2, 2, 1, 2, 2, 6, 2, 1, 6, 2, 1, 2, 3, 11, 11, 2, 2, 15, 15, 18, 18, 18, 18, 12, 12, 12, 1
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
EXAMPLE
| n=18: start = 262144 and the corresponding 11-cycle is 262144, 524286, [368640, 381024, 326592, 550368, 435456, 580608, 851840, 552960, 524160, 442368, 432000], 368640, ...
|
|
|
MATHEMATICA
| g[n_] := EulerPhi[ DivisorSigma[1, n]]; f[n_] := Block[{lst = NestWhileList[g, n, UnsameQ, All]}, -Subtract @@ Flatten[ Position[lst, lst[[ -1]]]]]; Table[ f[2^n], {n, 0, 20}]
|
|
|
CROSSREFS
| Cf. A095952, A095953, A095954, A095955, A095956, A096887, A096888, A096889, A096890, A096849, A096850.
Sequence in context: A177718 A057515 * A096857 A090000 A109082 A126303
Adjacent sequences: A096849 A096850 A096851 * A096853 A096854 A096855
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Jul 16 2004
|
|
|
EXTENSIONS
| Edited, corrected and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 17 2004
|
| |
|
|
