This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A061190 #26 Sep 08 2022 08:45:03
%S A061190 1,0,2,24,252,3120,46650,823536,16777208,387420480,9999999990,
%T A061190 285311670600,8916100448244,302875106592240,11112006825558002,
%U A061190 437893890380859360,18446744073709551600,827240261886336764160,39346408075296537575406,1978419655660313589123960
%N A061190 a(n) = n^n - n.
%C A061190 Number of endofunctions on [n] such that no element has a preimage of cardinality n. - _Alois P. Heinz_, Jul 21 2014
%H A061190 Vincenzo Librandi, <a href="/A061190/b061190.txt">Table of n, a(n) for n = 0..200</a>
%F A061190 E.g.f.: 1/(1 + LambertW(-x)) - x*exp(x), where LambertW() is the Lambert W-function. - _Ilya Gutkovskiy_, Feb 08 2017
%F A061190 a(n) = n*A037205(n-1). - _R. J. Mathar_, Jul 02 2017
%t A061190 Table[n^n-n, {n,25}] (* _Vladimir Joseph Stephan Orlovsky_, Dec 28 2010 *)
%o A061190 (Magma) [n^n - n : n in [0..20]]; // _Vincenzo Librandi_, Sep 01 2011
%Y A061190 Main diagonal of A245405.
%K A061190 nonn,easy
%O A061190 0,3
%A A061190 Lawrence H. Shirley (LShirley(AT)towson.edu), May 30 2001
%E A061190 a(0)=1 inserted by _Alois P. Heinz_, Jul 21 2014