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%I #11 Sep 18 2017 12:11:07
%S 2,5,6,14,8,27,20,33,24,65,28,90,48,68,72,152,60,189,88,138,120,275,
%T 104,270,168,261,180,434,128,495,272,350,288,444,228,702,360,492,336,
%U 860,264,945,460,564,528,1127,400,1071,520,848,648,1430,504,1140,696,1062,840,1769
%N a(n) = (n+1)*phi(n-1)/2.
%C The old entry with this sequence number was a duplicate of A082470.
%H J. Jaffe, <a href="http://www.jstor.org/stable/2689434">Permutation numbers</a>, Math. Mag., 49 (1976), 80-84.
%t Table[(n+1) EulerPhi[n-1]/2,{n,3,60}] (* _Harvey P. Dale_, Apr 22 2012 *)
%o (PARI) a(n) = (n+1)*eulerphi(n-1)/2; \\ _Michel Marcus_, Sep 18 2017
%K nonn
%O 3,1
%A _N. J. A. Sloane_, Nov 04 2008