|
| |
|
|
A053098
|
|
When the Euler phi function is iterated with initial value A002110(n)=primorial, a(n)= first (maximal) power of 2 emerging during iteration.
|
|
0
| |
|
|
2, 2, 8, 16, 128, 512, 8192, 16384, 262144, 2097152, 16777216, 67108864, 2147483648, 8589934592, 274877906944, 4398046511104, 70368744177664, 1125899906842624, 18014398509481984, 288230376151711744
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| Analogous to A053047 (the same with a similar large initial value, n!)
|
|
|
EXAMPLE
| n=6, A002110(6)=30030; the corresponding iteration chain is: {30030,5760,1536,512,256,128,64,32,16,8,4,2,1}. The first power of 2 is the 4-th item after 3 iterations.It is 512, therefore a(6)=512.
|
|
|
CROSSREFS
| A000010, A002110.
Sequence in context: A188115 A085542 A009725 * A194588 A175395 A169888
Adjacent sequences: A053095 A053096 A053097 * A053099 A053100 A053101
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Feb 28 2000
|
| |
|
|
