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A120582 Hankel transform of sum{k=0..floor(n/2), C(2k,k)}. 1
1, 2, 0, 0, -16, -32, -64, -128, 0, 0, 1024, 2048, 4096, 8192, 0, 0, -65536, -131072, -262144, -524288, 0, 0, 4194304, 8388608, 16777216, 33554432, 0, 0, -268435456, -536870912, -1073741824, -2147483648, 0, 0, 17179869184, 34359738368, 68719476736, 137438953472, 0, 0, -1099511627776 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Hankel transform of A100066(n+1).

LINKS

Table of n, a(n) for n=0..40.

FORMULA

a(n) = 2^n*(-sqrt(3)cos(5*Pi*n/6+Pi/3)/6 + (sqrt(3)/3-1/2)*sin(5*Pi*n/6+Pi/3) + (sqrt(3)/3+1/2)*cos(Pi*n/6+Pi/6) + sqrt(3)*sin(Pi*n/6+Pi/6)/6).

G.f.: -(2*x-1)*(2*x+1)^2 / (16*x^4-4*x^2+1). - Colin Barker, Jun 27 2013

CROSSREFS

Cf. A120580.

Sequence in context: A158465 A003193 A108474 * A003784 A244143 A066294

Adjacent sequences:  A120579 A120580 A120581 * A120583 A120584 A120585

KEYWORD

easy,sign

AUTHOR

Paul Barry, Jun 15 2006

STATUS

approved

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Last modified February 16 20:45 EST 2019. Contains 320189 sequences. (Running on oeis4.)