A114619 a(n) = 2*A079291(n) (twice squares of Pell numbers).

0, 2, 8, 50, 288, 1682, 9800, 57122, 332928, 1940450, 11309768, 65918162, 384199200, 2239277042, 13051463048, 76069501250, 443365544448, 2584123765442, 15061377048200, 87784138523762, 511643454094368

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (5,5,-1).

Formula

a(n) = 2*A000129(n)^2.

G.f.: 2*x*(1-x)/((1+x)*(1-6*x+x^2)).

a(n) = A001333(n)^2 - (-1)^n. - Antonio Pane (apane1(AT)spc.edu), Dec 15 2007

Mathematica

2*Fibonacci[Range[0, 30], 2]^2 (* G. C. Greubel, Aug 18 2022 *)

Prog

(Magma) [n le 3 select 2*(n-1)^2 else 5*Self(n-1) +5*Self(n-2) -Self(n-3): n in [1..31]]; // G. C. Greubel, Aug 18 2022
(SageMath) [2*lucas_number1(n, 2, -1)^2 for n in (0..30)] # G. C. Greubel, Aug 18 2022

Crossrefs

Cf. A000129, A001109, A001333, A001542, A079291.

Cf. also A090390, A108475, A114619, A116484.

Sequence in context: A046165 A227264 A373865 * A027047 A034491 A360949

Adjacent sequences: A114616 A114617 A114618 * A114620 A114621 A114622

Keyword

easy,nonn

Author

Creighton Dement, Feb 17 2006

Extensions

Entry revised by N. J. A. Sloane, Mar 15 2024

Status

approved