A122015 Expansion of a rational g.f., see formula.

1, 11, 41, 54, 129, 256, 529, 1083, 2233, 4606, 9505, 19611, 40513, 83657, 172805, 356963, 737425, 1523422, 3147277, 6502104, 13433121, 27752487, 57336161, 118455746, 244728361, 505606731, 1044579861, 2158095229, 4458611849

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (0,3,4,1,-4,-6,-4,-1).

Formula

G.f.: -x*(21*x^7+65*x^6+77*x^5+39*x^4-17*x^3-38*x^2-11*x-1)/((x+1)*(x^3+x^2-1)*(x^4+2*x^3+x^2+x-1)). [Colin Barker, Nov 02 2012]

Mathematica

CoefficientList[Series[-(21 x^7 + 65 x^6 + 77 x^5 + 39 x^4 - 17 x^3 - 38 x^2 - 11 x - 1)/((x + 1) (x^3 + x^2 - 1) (x^4 + 2 x^3 + x^2 + x - 1)), {x, 0, 33}], x] (* Vincenzo Librandi, Jun 15 2015 *)
LinearRecurrence[{0, 3, 4, 1, -4, -6, -4, -1}, {1, 11, 41, 54, 129, 256, 529, 1083}, 30] (* Harvey P. Dale, Jan 05 2023 *)

Crossrefs

Sequence in context: A158201 A350006 A370156 * A192820 A078653 A040167

Adjacent sequences: A122012 A122013 A122014 * A122016 A122017 A122018

Keyword

nonn,less,easy

Author

Roger L. Bagula, Sep 11 2006

Status

approved