A013205 Expansion of e.g.f. log(sech(x) + arctan(x)).

0, 1, -2, 3, -8, 53, -320, 1799, -14464, 154985, -1601152, 16589771, -211517440, 3172731677, -47440986112, 721614303695, -12501759557632, 241340829836497, -4730336839303168, 94965599172723859

Offset

0,3

Links

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

Example

x - 2/2!*x^2 + 3/3!*x^3 - 8/4!*x^4 + 53/5!*x^5 ...

Crossrefs

Sequence in context: A126464 A041979 A001686 * A340486 A245384 A292893

Adjacent sequences: A013202 A013203 A013204 * A013206 A013207 A013208

Keyword

sign

Author

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

Extensions

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

Status

approved