OFFSET
0,2
EXAMPLE
2*x - 1/2!*x^2 - 4/3!*x^3 + 18/4!*x^4 + 146/5!*x^5 ...
CROSSREFS
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
a(0)=0 inserted and title improved by Sean A. Irvine, Jul 31 2018
STATUS
approved