OFFSET
0,1
COMMENTS
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
G.f.: (485 + 2027*x + 10610*x^2)/(1-x)^3.
E.g.f.: (485 + 2997*x + 6561*x^2)*exp(x). - G. C. Greubel, Jun 21 2021
MATHEMATICA
LinearRecurrence[{3, -3, 1}, {485, 3482, 19601}, 40]
Table[6561n^2-3564n+485, {n, 0, 30}] (* Harvey P. Dale, Dec 09 2020 *)
PROG
(Magma) I:=[485, 3482, 19601]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]];
(PARI) a(n)= 6561*n^2-3564*n+485 \\ Charles R Greathouse IV, Dec 23 2011
(Sage) [485 -3564*n +6561*n^2 for n in (0..40)] # G. C. Greubel, Jun 21 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Feb 15 2009
EXTENSIONS
Edited by Charles R Greathouse IV, Jul 25 2010
STATUS
approved