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) = A110449(n, 7) for n>6.
a(n) = 15*n + a(n-1) - 7 for n>0, a(0)=0. - Vincenzo Librandi, Aug 04 2010
G.f.: x*(8+7*x)/(1-x)^3. - Vincenzo Librandi, Mar 31 2015
a(n) = 3*a(n-1) - 3*a(n-2) - a(n-3) for n>2. - Vincenzo Librandi, Mar 31 2015
a(n) = A022272(-n). - Bruno Berselli, Mar 31 2015
a(n) + a(-n) = A064761(n). - Bruno Berselli, Mar 31 2015
E.g.f.: (x/2)*(15*x + 16)*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 (8 + 7 x) / (1 - x)^3, {x, 0, 40}], x]; (* Vincenzo Librandi, Mar 31 2015 *)
PROG
(Magma) [n*(15*n + 1)/2: n in [0..45]]; // Vincenzo Librandi, Mar 31 2015
(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