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A017066 a(n) = (8*n)^2. 3
0, 64, 256, 576, 1024, 1600, 2304, 3136, 4096, 5184, 6400, 7744, 9216, 10816, 12544, 14400, 16384, 18496, 20736, 23104, 25600, 28224, 30976, 33856, 36864, 40000, 43264, 46656, 50176, 53824, 57600, 61504, 65536, 69696, 73984, 78400 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

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

G.f.: -64*x*(1+x)/(x-1)^3. - R. J. Mathar, Jul 14 2016

a(n) = A000290(8*n) = A008590(n)^2 = A000290(A008590(n).

From Amiram Eldar, Jan 25 2021: (Start)

Sum_{n>=1} 1/a(n) = Pi^2/384.

Sum_{n>=1} (-1)^(n+1)/a(n) = Pi^2/768.

Product_{n>=1} (1 + 1/a(n)) = sinh(Pi/8)/(Pi/8).

Product_{n>=1} (1 - 1/a(n)) = sin(Pi/8)/(Pi/8) = 4*sqrt(2-sqrt(2))/Pi. (End)

MATHEMATICA

LinearRecurrence[{3, -3, 1}, {0, 64, 256}, 50] (* Vincenzo Librandi, Feb 10 2012 *)

PROG

(MAGMA) [(8*n)^2: n in [0..35]]; // Vincenzo Librandi, Jul 10 2011

(PARI) a(n)=(8*n)^2 \\ Charles R Greathouse IV, Jun 17 2017

CROSSREFS

Cf. A000290, A008590.

Sequence in context: A263924 A236331 A321070 * A141478 A107262 A255662

Adjacent sequences:  A017063 A017064 A017065 * A017067 A017068 A017069

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified December 5 15:06 EST 2021. Contains 349557 sequences. (Running on oeis4.)