OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (7,-17,17,-6).
FORMULA
G.f.: (2-4*x-13*x^2+25*x^3)/((1-2*x)*(1-3*x)*(1-x)^2). - Bruno Berselli, Sep 01 2011
a(n) = 7*a(n-1)-17*a(n-2)+17*a(n-3)-6*a(n-4). - Vincenzo Librandi, Feb 26 2013
E.g.f.: exp(x)*(exp(x) + exp(2*x) + 5*x). - Stefano Spezia, May 06 2023
MATHEMATICA
CoefficientList[Series[(2 - 4 x - 13 x^2 + 25 x^3)/((1-2 x) (1-3 x) (1-x)^2), {x, 0, 30}], x] (* Vincenzo Librandi, Feb 26 2013 *)
LinearRecurrence[{7, -17, 17, -6}, {2, 10, 23, 50}, 30] (* Harvey P. Dale, Apr 28 2016 *)
PROG
(Magma) I:=[2, 10, 23, 50]; [n le 4 select I[n] else 7*Self(n-1)-17*Self(n-2)+17*Self(n-3)-6*Self(n-4): n in [1..30]]; // Vincenzo Librandi, Feb 26 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Aug 18 2006
EXTENSIONS
Edited by Ray Chandler, Sep 06 2006
STATUS
approved