OFFSET
0,1
COMMENTS
LINKS
Bruno Berselli, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
G.f.: (6 + 5*x - 2*x^2)/(1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
2*a(n) - a(n+1) + 12 = A081267(n).
E.g.f.: exp(x)*(12 + 34*x + 9*x^2)/2. - Elmo R. Oliveira, Nov 13 2024
MATHEMATICA
Table[n (9 n + 25)/2 + 6, {n, 0, 50}]
LinearRecurrence[{3, -3, 1}, {6, 23, 49}, 50] (* Harvey P. Dale, Feb 12 2022 *)
PROG
(Magma) [n*(9*n+25)/2+6: n in [0..50]];
(PARI) a(n)=n*(9*n+25)/2+6 \\ Charles R Greathouse IV, Oct 07 2015
CROSSREFS
KEYWORD
nonn,easy,changed
AUTHOR
Bruno Berselli, Jan 22 2014
STATUS
approved