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) = 15*n + a(n-1) - 8 for n>0, a(0)=0. - Vincenzo Librandi, Aug 04 2010
From Vincenzo Librandi, Mar 31 2015: (Start)
G.f.: x*(7 + 8*x)/(1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>2. (End)
From Bruno Berselli, Mar 31 2015: (Start)
a(n) = A022273(-n).
a(n) + a(-n) = A064761(n). (End)
E.g.f.: (x/2)*(15*x + 14)*exp(x). - G. C. Greubel, Aug 23 2017
MATHEMATICA
Table[n (15 n - 1)/2, {n, 0, 40}] (* Bruno Berselli, Mar 12 2015 *)
CoefficientList[Series[x (7 + 8 x) / (1 - x)^3, {x, 0, 40}], x] (* Vincenzo Librandi, Mar 31 2015 *)
LinearRecurrence[{3, -3, 1}, {0, 7, 29}, 50] (* Harvey P. Dale, Sep 15 2024 *)
PROG
(Magma) [n*(15*n - 1)/2: n in [0..45]]; // Vincenzo Librandi, Mar 31 20125
(PARI) a(n)=n*(15*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