OFFSET
0,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-2).
FORMULA
G.f.: (5 - 9*x)/((1 - x)*(1 - 2*x)). - Jaume Oliver Lafont, Aug 30 2009
a(n) = 2*a(n-1) - 4 with a(0) = 5. - Vincenzo Librandi, Nov 24 2009
From Reinhard Zumkeller, Feb 28 2010: (Start)
a(n) = A173786(n,2) for n > 1.
From G. C. Greubel, Jul 08 2021: (Start)
a(n) = m*(2^(n-2) + 1), with m = 4.
E.g.f.: exp(2*x) + 4*exp(x). (End)
MATHEMATICA
Table[2^n + 4, {n, 0, 30}] (* Stefan Steinerberger, Aug 04 2008 *)
LinearRecurrence[{3, -2}, {5, 6}, 40] (* Harvey P. Dale, May 26 2018 *)
PROG
(Sage) [2^n + 4 for n in range(0, 31)] # Zerinvary Lajos, May 31 2009
(PARI) a(n)=2^n+4 \\ Charles R Greathouse IV, Dec 21 2011
(Magma) [2^n +4: n in [0..30]]; // G. C. Greubel, Jul 08 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Jun 30 2008
EXTENSIONS
More terms from Stefan Steinerberger, Aug 04 2008
STATUS
approved