OFFSET
0,3
EXAMPLE
x + 2/2!*x^2 + 6/3!*x^3 + 24/4!*x^4 + 160/5!*x^5 ...
CROSSREFS
KEYWORD
nonn
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
a(0) inserted and title improved by Sean A. Irvine, Jul 24 2018
STATUS
approved