A013197 Expansion of e.g.f. log(sec(x) + sinh(x)).

0, 1, 0, 0, 4, -20, 120, -560, 2784, -7920, -24960, 1034880, -14625536, 172569280, -1661936640, 12339608320, -13269651456, -1902800305920, 53452617646080, -1037015219466240, 16547577836929024, -208832669083243520

Offset

0,5

Links

Table of n, a(n) for n=0..21.

Example

x + 4/4!*x^4 - 20/5!*x^5 + 120/6!*x^6 - 560/7!*x^7 ...

Crossrefs

Sequence in context: A091046 A101055 A208232 * A319788 A089498 A046729

Adjacent sequences: A013194 A013195 A013196 * A013198 A013199 A013200

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