OFFSET
1,2
COMMENTS
LINKS
Bruno Berselli, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (0,3,0,-3,0,1).
FORMULA
G.f.: x*(1 + 4*x + 3*x^2 + 4*x^3)/(1-x^2)^3. - Philippe Deléham, Mar 02 2012
a(n) = (n/4)*(3*n + (n-1)*(-1)^n + 1). - Bruno Berselli, Mar 02 2012
E.g.f.: (x/4)*(x*exp(-x) + (4 + 3*x)*exp(x)). - G. C. Greubel, Oct 21 2017
a(n) = 3*a(n-2) - 3*a(n-4) + a(n-6). - Wesley Ivan Hurt, Jun 08 2021
EXAMPLE
MATHEMATICA
Table[(n/4)*(3*n + (n - 1)*(-1)^n + 1), {n, 48}] (* Bruno Berselli, Mar 02 2012 *)
PROG
(PARI) for(n=1, 50, print1((n/4)*(3*n+(n-1)*(-1)^n+1), ", ")) \\ G. C. Greubel, Oct 21 2017
(Magma) [(n/4)*(3*n+(n-1)*(-1)^n+1): n in [1..50]]; // G. C. Greubel, Oct 21 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, Sep 09 2007
EXTENSIONS
Corrected and extended by Philippe Deléham, Mar 02 2012
STATUS
approved