A017018 a(n) = (7*n + 3)^2.

9, 100, 289, 576, 961, 1444, 2025, 2704, 3481, 4356, 5329, 6400, 7569, 8836, 10201, 11664, 13225, 14884, 16641, 18496, 20449, 22500, 24649, 26896, 29241, 31684, 34225, 36864, 39601, 42436, 45369, 48400

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..10000

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Formula

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3); a(0)=9, a(1)=100, a(2)=289. - Harvey P. Dale, Jul 19 2014

G.f.: (9 + 73*x + 16*x^2)/(1-x)^3. - Harvey P. Dale, Jul 19 2014

E.g.f.: (9 + 91*x + 49*x^2)*exp(x). - G. C. Greubel, Oct 17 2023

Mathematica

(7*Range[0, 40]+3)^2 (* or *) LinearRecurrence[{3, -3, 1}, {9, 100, 289}, 40] (* Harvey P. Dale, Jul 19 2014 *)

Prog

(Magma) [(7*n+3)^2: n in [0..35]]; // Vincenzo Librandi, Jul 14 2011
(PARI) a(n)=(7*n+3)^2 \\ Charles R Greathouse IV, Jun 17 2017
(SageMath) [(7*n+3)^2 for n in range(40)] # G. C. Greubel, Oct 17 2023

Crossrefs

Cf. A017017.

Sequence in context: A088780 A132544 A367353 * A027769 A266098 A065736

Adjacent sequences: A017015 A017016 A017017 * A017019 A017020 A017021

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved