login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A165752 a(n) = (8-5*4^n)/3. 2
1, -4, -24, -104, -424, -1704, -6824, -27304, -109224, -436904, -1747624, -6990504, -27962024, -111848104, -447392424, -1789569704, -7158278824, -28633115304, -114532461224, -458129844904, -1832519379624, -7330077518504 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..500

Index entries for linear recurrences with constant coefficients, signature (5,-4).

FORMULA

a(n) = 4*a(n-1) - 8, a(0)=1.

a(n) = 5*a(n-1) - 4*a(n-2), a(0)=1, a(1)=-4, for n>1.

G.f.: (1-9x)/(1-5x+4x^2).

a(n) = Sum_{0<=k<=n} A112555(n,k)*(-5)^(n-k).

a(n) = (-4)*A020989(n-1).

E.g.f.: (1/3)*(8*exp(x) - 5*exp(4*x)). - G. C. Greubel, Apr 07 2016

MATHEMATICA

(8-5*4^Range[0, 30])/3 (* or *) LinearRecurrence[{5, -4}, {1, -4}, 30] (* Harvey P. Dale, Jan 10 2016 *)

PROG

(PARI) x='x+O('x^99); Vec((1-9*x)/(1-5*x+4*x^2)) \\ Altug Alkan, Apr 07 2016

CROSSREFS

Sequence in context: A048806 A043009 A006736 * A166036 A120908 A145655

Adjacent sequences:  A165749 A165750 A165751 * A165753 A165754 A165755

KEYWORD

easy,sign

AUTHOR

Philippe Deléham, Sep 26 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 11 17:59 EST 2019. Contains 329925 sequences. (Running on oeis4.)