A012731 - OEIS

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A012731

arctan(arctanh(x)*arctan(x))=2/2!*x^2-32/6!*x^6+283392/10!*x^10...

2, -32, 283392, 1121740800, 157951397068800, 14184297129466920960, 5248874425245870210416640, 2544005109030684773416383283200 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`0,1`
	LINKS	`Table of n, a(n) for n=0..7.`
	MATHEMATICA	`With[{nn=30}, Take[CoefficientList[Series[ArcTan[ArcTanh[x]ArcTan[x]], {x, 0, nn}], x] Range[0, nn]!, {3, -1, 4}]] ( Ray Chandler, Nov 28 2016 *)`
	CROSSREFS	`Sequence in context: A128146 A185995 A012604 * A073402 A304145 A305485` `Adjacent sequences: A012728 A012729 A012730 * A012732 A012733 A012734`
	KEYWORD	`sign`
	AUTHOR	`Patrick Demichel (patrick.demichel(AT)hp.com)`
	STATUS	`approved`

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Last modified March 26 21:31 EDT 2023. Contains 361553 sequences. (Running on oeis4.)