|
| |
|
|
A053476
|
|
Smallest number m such that when A051953 is applied n times to m the result is neither a power of 2 nor 0.
|
|
0
|
|
|
|
9, 21, 42, 82, 130, 330, 450, 666, 1050, 1470, 1950, 2922, 4074, 5586, 7770, 11154, 15810, 22638, 30702, 42570, 53130, 68970, 107690, 159390, 206910, 289830, 395190, 610350, 823290, 1185570, 1522290, 2168250, 3011850, 4103490, 5364450
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
An analog for A000005 is A049117.
|
|
|
LINKS
|
Table of n, a(n) for n=1..35.
|
|
|
FORMULA
|
Applying cototient-function A051953 n+1 times to a(n), a power of 2 or 0 appears; a(n) is the smallest with this property.
|
|
|
EXAMPLE
|
a(6)=330 and the iteration of A051953 applied to 330 gives sequence {330,250,150,110,70,46,24,16,8,4,2,1,0}. Six iterations result in the 6th term 24 which still is neither a power of 2 nor 0. For smaller numbers than 330 these 6 iterations yield a power of 2 or the fixed number 0.
|
|
|
CROSSREFS
|
Cf. A051953, see also its iterates.
Sequence in context: A110209 A184040 A242990 * A110680 A163205 A154862
Adjacent sequences: A053473 A053474 A053475 * A053477 A053478 A053479
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Labos Elemer, Jan 14 2000
|
|
|
EXTENSIONS
|
More terms from Jud McCranie, Jan 14 2000
|
|
|
STATUS
|
approved
|
| |
|
|
