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

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A077845 Expansion of (1-x)^(-1)/(1-2*x-2*x^2-x^3). 0
 1, 3, 9, 26, 74, 210, 595, 1685, 4771, 13508, 38244, 108276, 306549, 867895, 2457165, 6956670, 19695566, 55761638, 157871079, 446961001, 1265425799, 3582644680, 10143101960, 28716919080, 81302686761, 230182313643, 651686919889, 1845041153826, 5223638461074 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Index entries for linear recurrences with constant coefficients, signature (3,0,-1,-1). FORMULA G.f.: (1-x)^(-1)/(1-2*x-2*x^2-x^3). a(n) = 3*a(n-1)-a(n-3)-a(n-4). - Wesley Ivan Hurt, Mar 10 2015 MATHEMATICA CoefficientList[Series[(1 - x)^(-1)/(1 - 2*x - 2*x^2 - x^3), {x, 0, 30}], x] (* Wesley Ivan Hurt, Mar 10 2015 *) PROG (PARI) Vec(1/((1-x)*(1-2*x-2*x^2-x^3)) + O(x^30)) \\ Michel Marcus, Mar 10 2015 CROSSREFS Sequence in context: A268093 A127911 A116423 * A291000 A276068 A171277 Adjacent sequences:  A077842 A077843 A077844 * A077846 A077847 A077848 KEYWORD nonn,easy AUTHOR N. J. A. Sloane, Nov 17 2002 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.

Last modified December 9 05:44 EST 2021. Contains 349627 sequences. (Running on oeis4.)