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A012463 tanh(arctan(x)*arctan(x))=2/2!*x^2-16/4!*x^4+128/6!*x^6+9984/8!*x^8... 0
0, 2, -16, 128, 9984, -1686528, 211630080, -21438504960, -115777536000, 1290343156285440, -677718502185369600, 262776565415742013440, -69499554745499013611520, -9137401716948937432104960 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Tanh[ArcTan[x]*ArcTan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Ray Chandler, Nov 28 2016 *)
CROSSREFS
Sequence in context: A161737 A171451 A012459 * A037517 A037720 A022018
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved

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Last modified March 29 11:14 EDT 2024. Contains 371278 sequences. (Running on oeis4.)