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!)
A249450 Alternate Fibonacci numbers - 2. 3
-2, -1, 1, 6, 19, 53, 142, 375, 985, 2582, 6763, 17709, 46366, 121391, 317809, 832038, 2178307, 5702885, 14930350, 39088167, 102334153, 267914294, 701408731, 1836311901, 4807526974, 12586269023, 32951280097, 86267571270, 225851433715, 591286729877 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
LINKS
FORMULA
G.f.: (-2+7*x-3*x^2)/(1-4*x+4*x^2-x^3).
a(n) = 4*a(n-1) - 4*a(n-2) + a(n-3) for n>2.
a(n) = 3*a(n-1) - a(n-2) + 2.
a(n) = (-2-((3-sqrt(5))/2)^n/sqrt(5)+((3+sqrt(5))/2)^n/sqrt(5)). - Colin Barker, Nov 03 2016
MATHEMATICA
Table[Fibonacci[2 n] - 2, {n, 0, 40}] (* or *) CoefficientList[Series[(-2 + 7 x - 3 x^2) / (1 - 4 x + 4 x^2 - x^3), {x, 0, 40}], x]
LinearRecurrence[{4, -4, 1}, {-2, -1, 1}, 30] (* Robert G. Wilson v, Dec 19 2014 *)
PROG
(Magma) [Fibonacci(2*n)-2: n in [0..40]];
(PARI) Vec((-2+7*x-3*x^2)/(1-4*x+4*x^2-x^3) + O(x^30)) \\ Colin Barker, Nov 03 2016
CROSSREFS
Sequence in context: A105291 A214631 A025270 * A331501 A247450 A178234
KEYWORD
sign,easy
AUTHOR
Vincenzo Librandi, Dec 15 2014
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 28 05:39 EDT 2024. Contains 371235 sequences. (Running on oeis4.)