OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-2).
FORMULA
a(n) = 2*a(n-1) + 3 with n > 0, a(0)=4.
G.f.: ( 4-x ) / ( (2*x-1)*(x-1) ). - R. J. Mathar, Oct 13 2011
MATHEMATICA
LinearRecurrence[{3, -2}, {4, 11}, 40] (* Vincenzo Librandi, Mar 01 2012 *)
PROG
(Magma) I:=[4, 11]; [n le 2 select I[n] else 3*Self(n-1)-2*Self(n-2): n in [1..40]]; // Vincenzo Librandi, Mar 01 2012
(PARI) a(n)=7*2^n-3 \\ Charles R Greathouse IV, Oct 16 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Feb 08 2009
EXTENSIONS
Corrected by R. J. Mathar, Oct 13 2011
STATUS
approved