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A012454 sec(arctan(x)*tan(x))=1+12/4!*x^4+17360/8!*x^8-241920/10!*x^10... 0
1, 0, 12, 0, 17360, -241920, 186158016, -11413642240, 7726026430720, -1212323504480256, 892608906281741312, -274005660019568705536, 234514059257417538031616, -119571044071522301122641920 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Sec[ArcTan[x]Tan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Jan 12 2016 *)
CROSSREFS
Sequence in context: A012338 A012453 A284453 * A322732 A370332 A370432
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved

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Last modified March 29 00:26 EDT 2024. Contains 371264 sequences. (Running on oeis4.)