|
Search: id:A049115
|
|
|
| A049115 |
|
Repeatedly apply Euler phi to n; a(n) = number of iterations that are applied to numbers that are not powers of 2. |
|
+0
2
|
|
| 0, 0, 1, 0, 1, 1, 2, 0, 2, 1, 2, 1, 2, 2, 1, 0, 1, 2, 3, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 1, 2, 0, 2, 1, 2, 2, 3, 3, 2, 1, 2, 2, 3, 2, 2, 3, 4, 1, 3, 2, 1, 2, 3, 3, 2, 2, 3, 3, 4, 1, 2, 2, 3, 0, 2, 2, 3, 1, 3, 2, 3, 2, 3, 3, 2, 3, 2, 2, 3, 1, 4, 2, 3, 2, 1, 3, 3, 2, 3, 2, 3, 3, 2, 4, 3, 1, 2, 3, 2, 2, 3, 1, 2, 2, 2
(list; graph; listen)
|
|
|
OFFSET
|
1,7
|
|
|
FORMULA
|
The smallest x so that Nest[ EulerPhi, n, x ] = 2^w is just achieved.
|
|
EXAMPLE
|
If n is a power of 2, then a(n)=0 by definition. If n=59049, then {59049,39366,13122,4374,1458,486,54,18,6,2,1}. This phi-sequence has a length of 12 and includes 10 non-2-powers, so a(59049)=8.
|
|
CROSSREFS
|
A000010.
Sequence in context: A039701 A025822 A051585 this_sequence A029367 A099302 A025814
Adjacent sequences: A049112 A049113 A049114 this_sequence A049116 A049117 A049118
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Labos E. (labos(AT)ana.sote.hu)
|
|
|
Search completed in 0.002 seconds
|
