|
Search: id:A049199
|
|
|
| A049199 |
|
Not-square-free numbers whose Euler totient function is also not square-free. |
|
+0
3
|
|
| 8, 12, 16, 20, 24, 25, 27, 28, 32, 36, 40, 44, 45, 48, 50, 52, 54, 56, 60, 63, 64, 68, 72, 75, 76, 80, 81, 84, 88, 90, 92, 96, 99, 100, 104, 108, 112, 116, 117, 120, 124, 125, 126, 128, 132, 135, 136, 140, 144, 147, 148, 150, 152, 153, 156, 160, 162, 164, 168, 169
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Prime powers of high enough exponents belong to here,like 16,32,64,..,27,81,..,25,125.
|
|
EXAMPLE
|
124=4*31 is here because Phi(124)=60.Neither 124,nor 60 are square-free.
|
|
MATHEMATICA
|
Abs[ MoebiusMu[ EulerPhi[ x ] ]]=0 and Abs[ MoebiusMu[ x ]]=0
|
|
CROSSREFS
|
A000010, A005117, A013929, A049198.
Adjacent sequences: A049196 A049197 A049198 this_sequence A049200 A049201 A049202
Sequence in context: A083348 A063539 A081925 this_sequence A078609 A084809 A110558
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Labos E. (labos(AT)ana.sote.hu)
|
|
|
Search completed in 0.002 seconds
|
