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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A108985 Expansion of (x+1)*(x^3-x^2-x-1)/((1-x)*(x^2+2*x-1)*(x^2+x+1)). 1
1, 4, 11, 27, 66, 161, 389, 940, 2271, 5483, 13238, 31961, 77161, 186284, 449731, 1085747, 2621226, 6328201, 15277629, 36883460, 89044551, 214972563, 518989678, 1252951921, 3024893521, 7302738964, 17630371451, 42563481867, 102757335186 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

A floretion-generated sequence calculated using the same rules given for A108618 with initial seed x = - .5'ii' - .5'jj' + .5'kk' - .5'jk' - .5'kj' + .5e; version: "tes". Note: replacing "tessum(*)seq" with "tesseq" in the program code gives A001333.

LINKS

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (2,1,1,-2,-1).

FORMULA

a(n) = 2*a(n-1) + a(n-2) + a(n-3) - 2*a(n-4) - a(n-5) for n>4. - Colin Barker, May 06 2019

PROG

2tessum(*)seq[ - .5'ii' - .5'jj' + .5'kk' - .5'jk' - .5'kj' + .5e] = 2tessum(*)seq[(- .5'i + .5'j - .5i' + .5j' - 'kk' - .5'ik' - .5'jk' - .5'ki' - .5'kj')*(.5'i + .5i')]

(PARI) Vec((1 + x)*(1 + x + x^2 - x^3) / ((1 - x)*(1 + x + x^2)*(1 - 2*x - x^2)) + O(x^30)) \\ Colin Barker, May 06 2019

CROSSREFS

Cf. A108618, A108986, A108987, A108988.

Sequence in context: A137229 A301874 A027439 * A014151 A176759 A266009

Adjacent sequences:  A108982 A108983 A108984 * A108986 A108987 A108988

KEYWORD

easy,nonn

AUTHOR

Creighton Dement, Jun 15 2005

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 October 18 23:39 EDT 2019. Contains 328211 sequences. (Running on oeis4.)