Expansion of e.g.f. sech(arctan(x)^2), even powers only.
A012467
Expansion of e.g.f. sech(arctan(x)^2), even powers only.
Terms
- a(0) =1a(1) =0a(2) =-12a(3) =480a(4) =-21168a(5) =741120a(6) =61942848a(7) =-29951061504
External references
- oeis: A012467