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A202621 Denominators of coefficients in Taylor series expansion of log(cotan(x)*arctan(x)). 1
1, 3, 15, 2835, 5670, 155925, 182432250, 1915538625, 390769879500, 1754068296605625, 29234471610093750, 2218896395206115625, 399401351137100812500, 9086380738369043484375, 5791319591487961781250, 28304394023345413370350078125, 3396527282801449604442009375000, 21652861427859241228317809765625 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..17.

EXAMPLE

-2/3*x^2+1/15*x^4-313/2835*x^6+317/5670*x^8-7813/155925*x^10+...

MATHEMATICA

Join[{1}, Denominator[Take[CoefficientList[Series[Log[Cot[x]ArcTan[x]], {x, 0, 40}], x], {3, -1, 2}]]] (* Harvey P. Dale, Nov 25 2012 *)

CROSSREFS

Cf. A012867.

Sequence in context: A016066 A012848 A322714 * A076046 A202380 A290610

Adjacent sequences:  A202618 A202619 A202620 * A202622 A202623 A202624

KEYWORD

nonn,frac

AUTHOR

N. J. A. Sloane, Dec 21 2011

STATUS

approved

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Last modified September 17 13:00 EDT 2019. Contains 327131 sequences. (Running on oeis4.)