OFFSET
1,1
COMMENTS
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..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.: x*(2024+2026*x)/(1-x)^3.
E.g.f.: x*(2024 + 2025*x)*exp(x). - G. C. Greubel, Jan 28 2022
MATHEMATICA
Table[n (2025*n - 1), {n, 40}] (* Wesley Ivan Hurt, Oct 10 2021 *)
PROG
(Magma) I:=[2024, 8098, 18222]; [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)=2025*n^2-n \\ Charles R Greathouse IV, Dec 23 2011
(Sage) [n*(2025*n -1) for n in (1..40)] # G. C. Greubel, Jan 28 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Feb 17 2009; corrected Feb 20 2009
STATUS
approved