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A066275 Number of endofunctions of [n] such that some element is fixed, but 1 is not fixed. 3
0, 1, 10, 111, 1476, 23255, 425958, 8915263, 210156040, 5513215599, 159374246010, 5034663700847, 172583816090700, 6380915666604583, 253132868797656526, 10725414213389814015, 483431164831317069840 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..17.

FORMULA

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).

EXAMPLE

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

MAPLE

A066275 := proc(n)

    n^n-n^(n-1)-(n-1)^n ;

end proc: # R. J. Mathar, Oct 31 2015

CROSSREFS

Cf. A045531, A066274.

Sequence in context: A176736 A084031 A210507 * A046164 A184131 A239651

Adjacent sequences:  A066272 A066273 A066274 * A066276 A066277 A066278

KEYWORD

nonn

AUTHOR

Len Smiley, Dec 09 2001

STATUS

approved

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Last modified February 22 04:10 EST 2018. Contains 299428 sequences. (Running on oeis4.)