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%I #26 Sep 08 2022 08:45:03
%S 1,0,2,24,252,3120,46650,823536,16777208,387420480,9999999990,
%T 285311670600,8916100448244,302875106592240,11112006825558002,
%U 437893890380859360,18446744073709551600,827240261886336764160,39346408075296537575406,1978419655660313589123960
%N a(n) = n^n - n.
%C Number of endofunctions on [n] such that no element has a preimage of cardinality n. - _Alois P. Heinz_, Jul 21 2014
%H Vincenzo Librandi, <a href="/A061190/b061190.txt">Table of n, a(n) for n = 0..200</a>
%F E.g.f.: 1/(1 + LambertW(-x)) - x*exp(x), where LambertW() is the Lambert W-function. - _Ilya Gutkovskiy_, Feb 08 2017
%F a(n) = n*A037205(n-1). - _R. J. Mathar_, Jul 02 2017
%t Table[n^n-n, {n,25}] (* _Vladimir Joseph Stephan Orlovsky_, Dec 28 2010 *)
%o (Magma) [n^n - n : n in [0..20]]; // _Vincenzo Librandi_, Sep 01 2011
%Y Main diagonal of A245405.
%K nonn,easy
%O 0,3
%A Lawrence H. Shirley (LShirley(AT)towson.edu), May 30 2001
%E a(0)=1 inserted by _Alois P. Heinz_, Jul 21 2014
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