|
| |
|
|
A065153
|
|
Numbers n such that cototient[totient[n]] - totient[cototient[n]] = 0.
|
|
1
| |
|
|
1, 3, 4, 8, 10, 14, 16, 18, 20, 28, 32, 33, 36, 40, 42, 54, 56, 64, 72, 75, 80, 84, 108, 110, 112, 114, 126, 128, 144, 160, 162, 168, 177, 198, 216, 220, 224, 228, 252, 256, 288, 320, 321, 324, 336, 342, 350, 375, 378, 396, 414, 432, 440, 448, 456, 486, 504, 512
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
LINKS
| Harry J. Smith, Table of n, a(n) for n=1,...,1000
|
|
|
EXAMPLE
| m=108, Phi[108]=36, 108-Phi[108]=72=cototient[108], cototient[36]=36-12=24, totient[72]=24, so 108 is here.
|
|
|
MATHEMATICA
| Flatten[Position[Table[co[eu[m]]-eu[co[m]], {m, 1, 1000}], 0]]
|
|
|
PROG
| (PARI) { n=0; for (m = 1, 10^9, t=eulerphi(m); c=m - t; if (m>1, f=t - eulerphi(t) - eulerphi(c), f=0); if (f==0, write("b065153.txt", n++, " ", m); if (n==1000, return)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Oct 13 2009]
|
|
|
CROSSREFS
| A000010[A051953(m)] = A051953[A000010(m)].
A000010, A051953.
Sequence in context: A114913 A111174 A075751 * A030497 A080085 A063414
Adjacent sequences: A065150 A065151 A065152 * A065154 A065155 A065156
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Oct 19 2001
|
| |
|
|
