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%I #39 Jun 24 2018 18:33:35
%S 10,90,730,5410,37900,264250,1908910,14322520,110305720,875799550,
%T 7203731050,60866700940,527138423380,4696469283970,42797376850150,
%U 397903278667600,3783002076771760,36604891556846470,360117919584474850,3603555076712108500
%N Number of n-digit decimal numbers with leading zeros allowed where no digit appears exactly twice.
%H Math Stackexchange, Marko Riedel et al., <a href="http://math.stackexchange.com/questions/1765530/">N digit numbers with no digit appearing exactly twice.</a>
%F E.g.f.: Sum_{q=1..N} C(10,q)*(exp(z)-z^2/2-1)^q.
%F E.g.f.: (exp(z)-z^2/2)^10.
%e Computing the value for n=1 the ten one-digit numbers 0-9 all qualify.
%e Computing the value for n=2 of two-digit numbers 00-99 all qualify except those consisting of a double digit (00, 11, ..., 99).
%p STNE2 := (n,k)->n!*coeftayl((exp(z)-z^2/2-1)^k/k!, z=0, n);
%p a(N) := N -> add(combinat:-binomial(10, q)*STNE2(N, q)*q!, q = 1 .. N)
%Y Cf. A272501, A272502, A272503.
%K nonn,base
%O 1,1
%A _Marko Riedel_, Apr 30 2016
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