A198769 a(n) = (9*5^n-1)/4.
2, 11, 56, 281, 1406, 7031, 35156, 175781, 878906, 4394531, 21972656, 109863281, 549316406, 2746582031, 13732910156, 68664550781, 343322753906, 1716613769531, 8583068847656, 42915344238281, 214576721191406, 1072883605957031, 5364418029785156, 26822090148925781
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (6,-5).
Programs
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Magma
[(9*5^n-1)/4: n in [0..30]];
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Mathematica
(9*5^Range[0,30]-1)/4 (* or *) LinearRecurrence[{6,-5},{2,11},30] (* Harvey P. Dale, May 07 2012 *)
Formula
a(n) = 5*a(n-1)+1.
a(n) = 6*a(n-1)-5*a(n-2), n>1.
G.f.: (2-x)/(5*x^2-6*x+1). - Harvey P. Dale, May 07 2012