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A013515 sech(sec(x)-sech(x))=1-12/4!*x^4+1568/8!*x^8+6840768/12!*x^12... 1

%I #9 Aug 02 2015 21:09:16

%S 1,-12,1568,6840768,-41485549312,-616649036623872,

%T 51689032519042469888,309411873154808535072768

%N sech(sec(x)-sech(x))=1-12/4!*x^4+1568/8!*x^8+6840768/12!*x^12...

%p A013515 := proc(n)

%p sech(sec(x)-sech(x)) ;

%p coeftayl( %,x=0,4*n) ;

%p %*(4*n)! ;

%p end proc: # _R. J. Mathar_, Dec 16 2011

%K sign

%O 0,2

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

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Last modified March 28 05:39 EDT 2024. Contains 371235 sequences. (Running on oeis4.)