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A104891 a(0) = 0; a(n) = 5*a(n-1) + 5.

%I A104891 #36 Sep 08 2022 08:45:17
%S A104891 0,5,30,155,780,3905,19530,97655,488280,2441405,12207030,61035155,
%T A104891 305175780,1525878905,7629394530,38146972655,190734863280,
%U A104891 953674316405,4768371582030,23841857910155,119209289550780,596046447753905,2980232238769530,14901161193847655
%N A104891 a(0) = 0; a(n) = 5*a(n-1) + 5.
%C A104891 Number of integers from 0 to (10^n)-1 that lack 0, 1, 2, 3 and 4 as a digit.
%C A104891 Number of monic irreducible polynomials of degree 1 in GF(5)[x1,...,xn]. - _Max Alekseyev_, Jan 23 2006
%H A104891 Harvey P. Dale, <a href="/A104891/b104891.txt">Table of n, a(n) for n = 0..1000</a>
%H A104891 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (6,-5).
%F A104891 a(n) = 5*(5^n - 1)/4. - _Max Alekseyev_, Jan 23 2006
%F A104891 a(n) = a(n-1) + 5^n with a(0)=0. - _Vincenzo Librandi_, Nov 13 2010
%F A104891 From _Colin Barker_, Jul 25 2014: (Start)
%F A104891 a(n) = 6*a(n-1) - 5*a(n-2).
%F A104891 G.f.: 5*x / ((1-x)*(1-5*x)). (End)
%F A104891 E.g.f.: (5/4)*(exp(5*x) - exp(x)). - _G. C. Greubel_, Jun 15 2021
%e A104891 a(3) = 5*a(2) + 5 = 5*30 + 5 = 155.
%p A104891 a:=n->add(5^j,j=1..n): seq(a(n),n=0..30); # _Zerinvary Lajos_, Jun 27 2007
%t A104891 RecurrenceTable[{a[n]==5*a[n-1]+5, a[0]==0}, a, {n, 0, 30}] (* Vaclav Kotesovec, Jul 25 2014 *)
%t A104891 NestList[5#+5&,0,30] (* _Harvey P. Dale_, Oct 04 2019 *)
%o A104891 (PARI) concat(0, Vec(5*x/((x-1)*(5*x-1)) + O(x^30))) \\ _Colin Barker_, Jul 25 2014
%o A104891 (Magma) [5*(5^n -1)/4: n in [0..30]]; // _G. C. Greubel_, Jun 15 2021
%o A104891 (Sage) [5*(5^n -1)/4 for n in (0..30)] # _G. C. Greubel_, Jun 15 2021
%Y A104891 Cf. A000225, A000918, A029858, A052379, A052386, A080674.
%Y A104891 Row n=5 of A228275.
%K A104891 easy,nonn
%O A104891 0,2
%A A104891 _Alexandre Wajnberg_, Apr 24 2005