A013197 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

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

(list; graph; refs; listen; history; text; internal format)

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