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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A121986 Expansion of x*(-1+2*x-3*x^3+x^4)/((x^3+x^2+x-1) * (x-1)^2). 1
 1, 1, 1, 4, 8, 16, 32, 61, 115, 215, 399, 738, 1362, 2510, 4622, 8507, 15653, 28797, 52973, 97440, 179228, 329660, 606348, 1115257, 2051287, 3772915, 6939483, 12763710, 23476134, 43179354, 79419226 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 LINKS G. C. Greubel, Table of n, a(n) for n = 1..1000 Index entries for linear recurrences with constant coefficients, signature (3, -2, 0, -1, 1). FORMULA a(n) = 3*a(n-1) -2*a(n-2) -a(n-4) +a(n-5). MATHEMATICA Rest[CoefficientList[Series[x*(-1 + 2*x - 3*x^3 + x^4)/((x^3 + x^2 + x - 1)*(x - 1)^2), {x, 0, 50}], x]] (* or *) LinearRecurrence[{3, -2, 0, -1, 1}, {1, 1, 1, 4, 8}, 50] (* G. C. Greubel, Sep 14 2017 *) PROG (PARI) x='x+O('x^50); Vec(x*(-1+2*x-3*x^3+x^4)/((x^3+x^2+x-1)*(x-1)^2)) \\ G. C. Greubel, Sep 14 2017 CROSSREFS Cf. A014125. Sequence in context: A007096 A298356 A036313 * A285906 A172042 A352918 Adjacent sequences: A121983 A121984 A121985 * A121987 A121988 A121989 KEYWORD nonn,easy AUTHOR Roger L. Bagula, Sep 09 2006 EXTENSIONS Definition replaced with generating function by the Assoc. Eds. of the OEIS, Mar 27 2010 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.

Last modified August 5 20:07 EDT 2024. Contains 374954 sequences. (Running on oeis4.)