A012504 - OEIS

A012504

tanh(cos(x)*arctan(x))=x-7/3!*x^3+165/5!*x^5-9931/7!*x^7...

1, -7, 165, -9931, 1037033, -167246319, 38489315917, -11958291252467, 4819985549046353, -2445005516326951767, 1523950240372673482357, -1144729097700954584840347, 1019812687197159075947289145

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..12.

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Tanh[Cos[x]ArcTan[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Nov 30 2025 *)

CROSSREFS

Sequence in context: A184754 A160241 A020998 * A012689 A098632 A385947

Adjacent sequences: A012501 A012502 A012503 * A012505 A012506 A012507

KEYWORD

sign

AUTHOR

Patrick Demichel

STATUS

approved