A168614 a(n) = 2^n + 5.

6, 7, 9, 13, 21, 37, 69, 133, 261, 517, 1029, 2053, 4101, 8197, 16389, 32773, 65541, 131077, 262149, 524293, 1048581, 2097157, 4194309, 8388613, 16777221, 33554437, 67108869, 134217733, 268435461, 536870917, 1073741829, 2147483653

Offset: 0

Author

Vincenzo Librandi, Dec 01 2009

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (3,-2).

Programs

Magma

[2^n+5: n in [0..40]]; // Vincenzo Librandi, Sep 19 2013

Mathematica

a[n_]:=2^n+5; a[Range[0,200]] (* Vladimir Joseph Stephan Orlovsky, Feb 20 2011*)
CoefficientList[Series[(6 - 11 x)/((1 - x) (1 - 2 x)), {x, 0, 40}], x] (* Vincenzo Librandi, Sep 19 2013 *)

PARI

a(n)=2^n+5 \\ Charles R Greathouse IV, Oct 27 2014

Formula

a(n) = 2*a(n-1) - 5 with n>0, a(0)=6.

From Colin Barker, Jul 01 2012: (Start)

a(n) = 3*a(n-1) - 2*a(n-2).

G.f.: (6 - 11*x)/((1-x)*(1-2*x)). (End)

E.g.f.: exp(2*x) + 5*exp(x). - G. C. Greubel, Jul 27 2016

Extensions

Checked by Michael B. Porter, Jun 16 2010