A024226 - OEIS

A024226

Expansion of sin(tan(x))*x/2.

0, 1, 2, -9, -1100, -75075, -5809002, -539002541, -59464355288, -7592385703239, -1074268351907350, -154802785066664977, -17096549995588876452, 2134127408928272414709, 3318524295428311509715966

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..14.

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Sin[Tan[x]]*x/2 , {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Jan 02 2024 *)

CROSSREFS

Cf. A009508.

Sequence in context: A253604 A067691 A062840 * A252584 A305851 A208207

Adjacent sequences: A024223 A024224 A024225 * A024227 A024228 A024229

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs Mar 1997

Previous Mathematica program replaced by Harvey P. Dale, Jan 02 2024

STATUS

approved