OFFSET
0,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
From Wesley Ivan Hurt, Dec 22 2020: (Start)
G.f.: 4*(25 + 46*x + x^2)/(1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n >= 3.
a(n) = 144*n^2 + 240*n + 100.
a(n) = A017641(n)^2. (End)
EXAMPLE
a(5) = (12*5+10)^2 = 70^2 = 4900.
MATHEMATICA
(12*Range[0, 30]+10)^2 (* or *) LinearRecurrence[{3, -3, 1}, {100, 484, 1156}, 30] (* Harvey P. Dale, May 08 2017 *)
CoefficientList[Series[4*(25 + 46 x + x^2)/(1 - x)^3, {x, 0, 40}], x] (* Wesley Ivan Hurt, Dec 22 2020 *)
PROG
(PARI) a(n)=(12*n+10)^2 \\ Charles R Greathouse IV, Jun 17 2017
(Magma) [(12*n+10)^2 : n in [0..40]]; // Wesley Ivan Hurt, Dec 22 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved