login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A084431 Expansion of (1 + 6*x + 5*x^2)/((1-2*x)*(1+2*x)). 2
1, 6, 9, 24, 36, 96, 144, 384, 576, 1536, 2304, 6144, 9216, 24576, 36864, 98304, 147456, 393216, 589824, 1572864, 2359296, 6291456, 9437184, 25165824, 37748736, 100663296, 150994944, 402653184, 603979776, 1610612736, 2415919104 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Binomial transform is A085287.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (0,4)

FORMULA

a(n) = (-10*0^n - 3*(-2)^n + 21*2^n)/8.

a(n) = 4*a(n-2), n > 1.  - Harvey P. Dale, Nov 05 2011

MATHEMATICA

CoefficientList[Series[(1+6x+5x^2)/((1-2x)(1+2x)), {x, 0, 30}], x] (* or *) Join[{1}, Flatten[NestList[4#&, {6, 9}, 15]]] (* Harvey P. Dale, Nov 05 2011 *)

PROG

(MAGMA) [(-10*0^n-3*(-2)^n+21*2^n)/8: n in [0..30]]; // Vincenzo Librandi, Nov 16 2011

CROSSREFS

Bisections are A002023 and A002063.

Sequence in context: A034718 A215528 A155577 * A176498 A142877 A260168

Adjacent sequences:  A084428 A084429 A084430 * A084432 A084433 A084434

KEYWORD

nonn,easy

AUTHOR

Paul Barry, Jun 26 2003

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 May 18 19:58 EDT 2021. Contains 344002 sequences. (Running on oeis4.)