OFFSET
0,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (3,-2,-2,3,-1).
FORMULA
G.f.: (2*x^2+x^3)/((1-x)^3*(1-x^2)). - Michael Somos
a(n) = (1/16)*(2*n*(2*n^2+n-2)+(-1)^n-1). - Bruno Berselli, Aug 29 2011
E.g.f.: (x*(1 + 7*x + 2*x^2)*cosh(x) - (1 - x - 7*x^2 - 2*x^3)*sinh(x))/8. - Stefano Spezia, Aug 22 2023
MATHEMATICA
LinearRecurrence[{3, -2, -2, 3, -1}, {0, 0, 2, 7, 17}, 45] (* Jean-François Alcover, Dec 12 2016 *)
CoefficientList[Series[(2x^2+x^3)/((1-x)^3(1-x^2)), {x, 0, 50}], x] (* Harvey P. Dale, Jun 26 2021 *)
PROG
(PARI) a(n)=(4*n^3+2*n^2-4*n)\16
(Magma) [Floor((4*n^3+2*n^2-4*n)/16): n in [0..50]]; // Vincenzo Librandi, Aug 29 2011
CROSSREFS
KEYWORD
nonn,easy,nice
AUTHOR
STATUS
approved