A013289 Expansion of e.g.f. tanh(log(x+1) - tanh(x)).

0, 0, -1, 4, -6, 8, -90, 152, 6440, -69984, 451080, -4819168, 67077648, -533622208, 882593712, 16010702528, -325947073920, 15149145074176, -402497641556352, 6097893929134592, -75930618112953600, 1338998058465717248, -21267088125132503808

Offset

0,4

Links

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

Example

-(1/2!)*x^2 + (4/3!)*x^3 - (6/4!)*x^4 + (8/5!)*x^5 - ...

Mathematica

Range[0, 25]! CoefficientList[Series[Tanh[Log[x + 1] - Tanh[x]], {x, 0, 25}], x] (* Vincenzo Librandi, Aug 03 2018 *)

Prog

(Magma)  m:=30; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(1+Tanh(Log(x+1) - Tanh(x)))); [0] cat [Factorial(n-1)*b[n]: n in [2..m]]; // Vincenzo Librandi, Aug 03 2018

Crossrefs

Sequence in context: A203633 A190630 A013285 * A013288 A013282 A013287

Adjacent sequences: A013286 A013287 A013288 * A013290 A013291 A013292

Keyword

sign

Author

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

Extensions

a(0)=a(1)=0 inserted and title improved by Sean A. Irvine, Aug 03 2018

Status

approved