|
Search: id:A060610
|
|
|
| A060610 |
|
Repeatedly apply Euler phi to n-th prime; a(n) is the number terms in iteration chains which are not powers of 2 (number of initial iterations until reaching first power of 2). |
|
+0
1
|
|
| 0, 1, 1, 2, 2, 2, 1, 3, 3, 3, 2, 3, 2, 3, 4, 3, 4, 2, 3, 3, 3, 3, 3, 3, 2, 3, 2, 4, 4, 3, 4, 3, 2, 4, 4, 3, 3, 5, 4, 4, 4, 3, 4, 2, 4, 3, 3, 4, 4, 4, 4, 3, 2, 4, 1, 4, 4, 4, 4, 3, 5, 4, 3, 3, 3, 4, 3, 3, 5, 4, 3, 5, 3, 3, 5, 5, 3, 3, 3, 2, 4, 3, 4, 4, 4, 3, 3, 4, 4, 3, 5, 4, 6, 4, 4, 5, 5, 3, 4, 4, 4, 5, 4, 4, 4
(list; graph; listen)
|
|
|
OFFSET
|
1,4
|
|
|
FORMULA
|
a(n)=A049115[A000040(n)]
|
|
EXAMPLE
|
n=100,p(100)=541, Phi-iteration chain is {541,540,144,48,16,8,4,2,1} with 9 terms. The first 4 terms (541,540,144,48) are not powers of 2, som a(100)=4.
|
|
CROSSREFS
|
Cf. A000040, A000010, A049108, A049113, A049116, A049115, A003434.
Sequence in context: A064659 A127953 A130267 this_sequence A017125 A063276 A055253
Adjacent sequences: A060607 A060608 A060609 this_sequence A060611 A060612 A060613
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Labos E. (labos(AT)ana.sote.hu), Apr 13 2001
|
|
|
Search completed in 0.002 seconds
|
