STATUS
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approved
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proposed
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proposed
a(n) = (8*10^n - 17)/9 for n > 0.
7, 87, 887, 8887, 88887, 888887, 8888887, 88888887, 888888887, 8888888887, 88888888887, 888888888887, 8888888888887, 88888888888887, 888888888888887, 8888888888888887, 88888888888888887, 888888888888888887, 8888888888888888887, 88888888888888888887, 888888888888888888887
a(n) = 10*a(n-1) + 17 with n > 0, a(0)=-1.
From Vincenzo Librandi, Jul 05 2012: (Start)
a(n) = 11*a(n-1) - 10*a(n-2) for n > 2. - _Vincenzo Librandi_, Jul 05 2012
G.f.: x*(7+10*x)/((1-x)*(1-10*x)). - _Vincenzo Librandi_, Jul 05 2012(End)
E.g.f.: 1 + exp(x)*(8*exp(9*x) - 17)/9. - Elmo R. Oliveira, Sep 09 2024
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(MAGMAMagma) [(8*10^n-17)/9: n in [1..20]]; // Vincenzo Librandi, Jul 05 2012
<a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).
<a href="/index/Rec">Index to sequences with entries for linear recurrences with constant coefficients</a>, signature (11,-10).
<a href="/index/Rec#recLCC">Index to sequences with linear recurrences with constant coefficients</a>, signature (11,-10).
<a href="/Sindx_Rea.htmlindex/Rec#recLCC">Index to sequences with linear recurrences with constant coefficients</a>, signature (11,-10).
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Table[FromDigits[PadLeft[{7}, n, 8]], {n, 20}] (* Harvey P. Dale, Jun 22 2013 *)
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