A017294 a(n) = (10*n + 2)^2.

4, 144, 484, 1024, 1764, 2704, 3844, 5184, 6724, 8464, 10404, 12544, 14884, 17424, 20164, 23104, 26244, 29584, 33124, 36864, 40804, 44944, 49284, 53824, 58564, 63504, 68644, 73984, 79524, 85264, 91204, 97344, 103684, 110224, 116964, 123904, 131044, 138384

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) = a(n-1) + 200*n - 60, n>0 ; a(0)=4. - Miquel Cerda, Oct 30 2016

G.f.: 4*(1 + 33*x + 16*x^2)/(1 - x)^3. - Ilya Gutkovskiy, Oct 30 2016

a(n) = A017293(n)^2. - Michel Marcus, Oct 30 2016

a(n) = (2*A016861(n))^2. - David A. Corneth, Oct 30 2016

From Elmo R. Oliveira, Sep 10 2025: (Start)

E.g.f.: 4*exp(x)*(1 + 35*x + 25*x^2).

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).

a(n) = A016874(2*n). (End)

Mathematica

(10 Range[0, 50] + 2)^2 (* Wesley Ivan Hurt, Sep 04 2022 *)

Prog

(Magma) [(10*n+2)^2: n in [0..35]]; // Vincenzo Librandi, Jul 30 2011
(PARI) a(n)=(10*n+2)^2 \\ Charles R Greathouse IV, Jun 17 2017

Crossrefs

First bisection of A016874.

Cf. A016861, A017293.

Sequence in context: A058414 A053891 A053897 * A273698 A134631 A036511

Adjacent sequences: A017291 A017292 A017293 * A017295 A017296 A017297

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved