A047685 Numerators of coefficients in Taylor series for log(tan(x)/x).

0, 1, 7, 62, 127, 146, 1414477, 32764, 16931177, 11499383114, 91546277357, 13299018868, 1982765468311237, 88306001369044, 130106068440304534, 7400951287808330864888, 16555640865486520478399, 16179883156293315362

Offset

0,3

References

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

Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 34, equation 34:6:3 at page 323.

Links

Table of n, a(n) for n=0..17.

Example

(1/3)*x^2 + (7/90)*x^4 + (62/2835)*x^6 + (127/18900)*x^8 + (146/66825)*x^10 + ...

Mathematica

Join[{0}, DeleteCases[Numerator[CoefficientList[Series[Log[Tan[x]/x], {x, 0, 34}], x]], 0]] (* Stefano Spezia, Jan 03 2025 *)

Crossrefs

Cf. A047686.

Sequence in context: A317430 A145507 A254121 * A171078 A368057 A180776

Adjacent sequences: A047682 A047683 A047684 * A047686 A047687 A047688

Keyword

nonn,easy,frac

Author

N. J. A. Sloane

Status

approved