A013236 Expansion of e.g.f. tan(log(x+1) - tan(x)).

0, 0, -1, 0, -6, 8, -150, 448, -7560, 38432, -642600, 4827328, -83392848, 846371264, -15413462064, 198308799232, -3850826179200, 59939510237696, -1248952432920192, 22723443584373760, -509532711855338240, 10564033699974222848, -255033199091475264768

Offset: 0

Author

Patrick Demichel (patrick.demichel(AT)hp.com)

Keywords

• sign

Examples

			-1/2!*x^2 - 6/4!*x^4 + 8/5!*x^5 - 150/6!*x^6 ...
		

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..200

Programs

Mathematica

Range[0, 25]! CoefficientList[Series[Tan[Log[x + 1] - Tan[x]], {x, 0, 25}], x] (* Vincenzo Librandi, Aug 02 2018 *)

PARI

x = 'x + O('x^30); concat([0, 0], Vec(serlaplace(tan(log(x+1) - tan(x))))) \\ Michel Marcus, Aug 02 2018

Extensions

a(0)=a(1)=0 inserted and title improved by Sean A. Irvine, Aug 01 2018