A068556 From numerators in expansion of tan(arcsinh(x)) - sin(arctanh(x)).

0, 0, 0, 0, 4, 4, 377, 1202, 133211, 1082357, 3730351411, 6203235575, 28719995819965, 2124563380903465, 122827509141846335, 42344667805954043, 1305035883448960477, 36723101348641621053659, 384279850938174722635253, 71260765129276904394438865

Offset

0,5

References

R. W. Gosper, personal communication, Mar 07, 2002, who asks if the coefficients are always nonnegative.

Links

Table of n, a(n) for n=0..19.

Example

4/189*x^9+4/189*x^11+377/12474*x^13+1202/43659*x^15+...

Crossrefs

Cf. A068557.

Sequence in context: A218050 A107052 A000790 * A078243 A024246 A358199

Adjacent sequences: A068553 A068554 A068555 * A068557 A068558 A068559

Keyword

nonn,frac

Author

N. J. A. Sloane, Mar 23 2002

Status

approved