OFFSET
3,1
COMMENTS
The old entry with this sequence number was a duplicate of A082470.
LINKS
J. Jaffe, Permutation numbers, Math. Mag., 49 (1976), 80-84.
MATHEMATICA
Table[(n+1) EulerPhi[n-1]/2, {n, 3, 60}] (* Harvey P. Dale, Apr 22 2012 *)
PROG
(PARI) a(n) = (n+1)*eulerphi(n-1)/2; \\ Michel Marcus, Sep 18 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 04 2008
STATUS
approved