A024262 Expansion of tanh(sin(x)^2)/2.

0, 1, -4, -104, 6656, -40064, -42409984, 4996996096, 379877605376, -280033142964224, 36077603872833536, 18835361007974219776, -11364456303888437346304, 367251340814801013047296, 3076185618615703435483283456, -1692496413849432696569477464064

Offset

0,3

Links

Table of n, a(n) for n=0..15.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Tanh[Sin[x]^2]/2, {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Jun 03 2014 *)

Crossrefs

Cf. A009801.

Sequence in context: A302733 A098696 A013054 * A012958 A012984 A202683

Adjacent sequences: A024259 A024260 A024261 * A024263 A024264 A024265

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs Mar 1997

More terms from and prior Mathematica program replaced by Harvey P. Dale, Jun 03 2014

Status

approved