A013443 - OEIS

%I #4 Feb 24 2012 12:51:29

%S 4,-8,992,3456,2799872,106544128,37168683008,4255728041984,

%T 1543239875821568,355403465489907712,155864209273777553408,

%U 58585654628727325196288,32351390426329866422976512

%N tan(tan(x)-arctan(x))=4/3!*x^3-8/5!*x^5+992/7!*x^7+3456/9!*x^9...

%K sign

%O 0,1

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