login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A155607 9^n+3^n-1. 13
1, 11, 89, 755, 6641, 59291, 532169, 4785155, 43053281, 387440171, 3486843449, 31381236755, 282430067921, 2541867422651, 22876797237929, 205891146443555, 1853020231898561, 16677181828806731, 150094635684419609 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
G.f.: 1/(1-9*x)+1/(1-3*x)-1/(1-x). E.g.f.: e^(9*x)+e^(3*x)-e^x.
a(n)=12*a(n-1)-27*a(n-2)-16 with a(0)=1, a(1)=11 - Vincenzo Librandi, Jul 21 2010
MATHEMATICA
LinearRecurrence[{13, -39, 27}, {1, 11, 89}, 20] (* Harvey P. Dale, Dec 29 2018 *)
PROG
(PARI) a(n)=9^n+3^n-1 \\ Charles R Greathouse IV, Jun 11 2015
CROSSREFS
Sequence in context: A081657 A226854 A037580 * A356323 A110252 A199394
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jan 25 2009
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 3 03:04 EST 2024. Contains 370499 sequences. (Running on oeis4.)