OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,-4).
FORMULA
G.f.: 2*(1-3*x^2+2*x^3)/((1-x)^2*(1-2*x)^2). - Vincenzo Librandi, Sep 02 2016
Sum_{n>=0} 1/a(n) = A196525. - Fred Daniel Kline, May 24 2019
MATHEMATICA
CoefficientList[Series[2 (1 - 3 x^2 + 2 x^3)/((1 - x)^2 (1 - 2 x)^2), {x, 0, 30}], x] (* Vincenzo Librandi, Sep 02 2016 *)
Table[(2n+1)2^(n+1), {n, 0, 30}] (* or *) LinearRecurrence[{4, -4}, {2, 12}, 30] (* Harvey P. Dale, Oct 25 2021 *)
PROG
(Magma) [(2*n+1)*2^(n+1): n in [0..40]]; // Vincenzo Librandi, Dec 26 2010
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Reinhard Zumkeller, Apr 27 2006
STATUS
approved