|
Search: id:A053475
|
|
|
| A053475 |
|
1 + the number of iterations of A051953 (Euler-cototient) function needed to reach 0, starting at n (n is counted). |
|
+0
11
|
|
| 2, 3, 3, 4, 3, 5, 3, 5, 4, 6, 3, 6, 3, 6, 4, 6, 3, 7, 3, 7, 5, 7, 3, 7, 4, 7, 5, 7, 3, 8, 3, 7, 4, 8, 4, 8, 3, 8, 5, 8, 3, 9, 3, 8, 6, 8, 3, 8, 4, 9, 4, 8, 3, 9, 5, 8, 6, 9, 3, 9, 3, 8, 6, 8, 4, 9, 3, 9, 5, 9, 3, 9, 3, 9, 5, 9, 4, 10, 3, 9, 6, 10, 3, 10, 6, 9, 4, 9, 3, 10, 4, 9, 5, 9, 4, 9, 3, 9, 6, 10, 3, 10
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Analogous sequences of iteration-lengths for A000005 or A000010 are A036459 and A049108 resp. The length values of 3 occur if the initial value is prime resulting in {p,1,0} iterations.
|
|
FORMULA
|
Smallest number of steps j such that Nest[cototient, n, j]=0, where cototient[n] = n - EulerPhi[n]
|
|
EXAMPLE
|
Starting with n=100, the iterations of A051953 are as follows: {100,60,44,24,16,8,4,2,1,0}. The length of this sequence generated by 100 is a[n]= a[100]. The function is applied a[n]-1 times
|
|
CROSSREFS
|
A000005, A000010, A051953, A036459, A049108.
Sequence in context: A086925 A088858 A113312 this_sequence A049878 A038203 A096827
Adjacent sequences: A053472 A053473 A053474 this_sequence A053476 A053477 A053478
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Labos E. (labos(AT)ana.sote.hu), Jan 14 2000
|
|
|
Search completed in 0.002 seconds
|
