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A008991 Numerators of coefficients in expansion of sqrt(sin(x)/x) (even powers only). 5
1, -1, 1, -1, -67, -1, -64397, -113249, -3679787, -810304169, -6040635661561, -428305999661, -16827172241810597, -5620292762592913, -1550760014054450957, -4168373361283100017, -8551022502876237590534947 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..255

Weisstein Eric W. The Sinc Function,  Wolfram Mathworld.

FORMULA

sum(n>=0, A008991(n)/A008992(n) ) = A117017 - Johannes W. Meijer, Feb 10 2013

MAPLE

A008991 := n -> numer(coeff(taylor(sqrt(sin(x)/x), x, 2*n+2), x, 2*n)):  seq(A008991(n), n=0..16); # Johannes W. Meijer, Feb 10 2013

MATHEMATICA

Numerator[CoefficientList[Series[Sqrt[Sin[x]/x], {x, 0, 50}], x][[1 ;; -1 ;; 2]]] (* G. C. Greubel, Jul 21 2018 *)

PROG

(Sage)

len = 16; T = taylor(sqrt(sin(x)/x), x, 0, 2*len+2)

[T.coeff(x, 2*n).numerator() for n in (0..len)]

# Peter Luschny, Dec 13 2012

CROSSREFS

Denominators are in A008992.

Appears in A220002 and A220466.

Sequence in context: A110150 A295790 A246241 * A051323 A112506 A033387

Adjacent sequences:  A008988 A008989 A008990 * A008992 A008993 A008994

KEYWORD

sign

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified May 19 08:25 EDT 2019. Contains 323389 sequences. (Running on oeis4.)