|
Search: id:A064852
|
|
| |
|
| 1, 0, 0, 1, 4, 18, 102, 624, 4476, 36248, 329890, 3326054, 36846276, 444783906, 5811885808, 81729607680, 1230752346352, 19760412095328, 336967037143578, 6082255011151724, 115852476579789984, 2322315553090615850
(list; graph; listen)
|
|
|
OFFSET
|
1,5
|
|
|
FORMULA
|
a(n) = Sum_{k|n} mu(n/k)*phi(n/k)*(n/k)^k*k!/n^2 = A047918(n, n)/n^2.
|
|
EXAMPLE
|
n=6: The orbit {(124635)(235146)(346251)(451362)(562413)(613524)} consists of 6 single permutations
|
|
PROGRAM
|
(PARI) for(n=1, 23, print(sumdiv(n, d, moebius(n/d)*eulerphi(n/d)*(n/d)^d*d!/n^2)))
|
|
CROSSREFS
|
Cf. A002619.
Sequence in context: A084832 A135177 A137958 this_sequence A051827 A007711 A020114
Adjacent sequences: A064849 A064850 A064851 this_sequence A064853 A064854 A064855
|
|
KEYWORD
|
nice,nonn
|
|
AUTHOR
|
Michael Steyer (m.steyer(AT)osram.de), Oct 06 2001
|
|
EXTENSIONS
|
Corrected and extended by Jason Earls (jcearls(AT)cableone.net) and Vladeta Jovovic (vladeta(AT)Eunet.yu), Oct 08 2001
|
|
|
Search completed in 0.002 seconds
|
