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URL: https://oeis.org/A066275

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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
OFFSET
1,3
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
MATHEMATICA
Table[n^n-n^(n-1)-(n-1)^n, {n, 20}] (* Harvey P. Dale, Nov 29 2025 *)
CROSSREFS
Sequence in context: A176736 A084031 A210507 * A362671 A344398 A046164
KEYWORD
nonn
AUTHOR
Len Smiley, Dec 09 2001
STATUS
approved