A047691 Numerators of coefficients in Taylor series for exp(tan(x)).

1, 1, 1, 1, 3, 37, 59, 137, 871, 41641, 325249, 3887, 35797, 241586893, 24362249, 5721418891, 342232522657, 4315903789009, 8224154352439, 2832484672207, 23157229065769, 183184249105857781, 9926476934520521, 2154299222076719401

Offset

0,5

References

CRC Standard Mathematical Tables and Formulae, 30th ed. 1996, p. 42.

Links

Table of n, a(n) for n=0..23.

Example

1 + 1*x + (1/2)*x^2 + (1/2)*x^3 + (3/8)*x^4 + (37/120)*x^5 + (59/240)*x^6 + (137/720)*x^7 + (871/5760)*x^8 + ...

Mathematica

Numerator[CoefficientList[Series[Exp[Tan[x]], {x, 0, 30}], x]] (* Harvey P. Dale, May 19 2015 *)

Crossrefs

Cf. A047692, A006229.

Sequence in context: A106996 A338751 A300347 * A323829 A139842 A091824

Adjacent sequences: A047688 A047689 A047690 * A047692 A047693 A047694

Keyword

nonn,easy,frac

Author

N. J. A. Sloane

Status

approved