OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..5000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
a(n) = 19*n + a(n-1) - 10 for n>0, a(0)=0. - Vincenzo Librandi, Aug 04 2010
From Vincenzo Librandi, Mar 31 2015: (Start)
G.f.: x*(9 + 10*x)/(1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>2. (End)
a(n) = A022277(-n). - Bruno Berselli, Apr 01 2015
E.g.f.: (x/2)*(19*x + 18)*exp(x). - G. C. Greubel, Aug 23 2017
MATHEMATICA
Table[n (19 n - 1)/2, {n, 0, 40}] (* Bruno Berselli, Mar 12 2015 *)
CoefficientList[Series[x (9 + 10 x) / (1 - x)^3, {x, 0, 40}], x] (* Vincenzo Librandi, Mar 31 2015 *)
LinearRecurrence[{3, -3, 1}, {0, 9, 37}, 50] (* Harvey P. Dale, Jul 25 2021 *)
PROG
(Magma) [n*(19*n - 1)/2: n in [0..45]]; // Vincenzo Librandi, Mar 31 2015
(PARI) a(n)=n*(19*n-1)/2 \\ Charles R Greathouse IV, Jun 17 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
More terms from Vincenzo Librandi, Mar 31 2015
STATUS
approved