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Number of endofunctions of [n] such that some element is fixed, but 1 is not fixed.
3

%I #6 Oct 31 2015 14:17:29

%S 0,1,10,111,1476,23255,425958,8915263,210156040,5513215599,

%T 159374246010,5034663700847,172583816090700,6380915666604583,

%U 253132868797656526,10725414213389814015,483431164831317069840

%N Number of endofunctions of [n] such that some element is fixed, but 1 is not fixed.

%F a(n) = n^n-n^(n-1)-(n-1)^n. E.g.f.: (T^3-T^2+T-x)/(T-T^2), where T=T(x) is Euler's tree function (see A000169).

%e a(2)=1: [1->2,2->2].

%p A066275 := proc(n)

%p n^n-n^(n-1)-(n-1)^n ;

%p end proc: # _R. J. Mathar_, Oct 31 2015

%Y Cf. A045531, A066274.

%K nonn

%O 1,3

%A _Len Smiley_, Dec 09 2001