E.g.f. C(x) satisfies: C(x)^2 - S(x)^2 = 1 and C'(x)^2 + S'(x)^2 = 1, where S(x) is the e.g.f. of A290881.

A290880

E.g.f. C(x) satisfies: C(x)^2 - S(x)^2 = 1 and C'(x)^2 + S'(x)^2 = 1, where S(x) is the e.g.f. of A290881.

Terms

    a(0) =1a(1) =1a(2) =-7a(3) =265a(4) =-24175a(5) =4037425a(6) =-1070526775a(7) =412826556025

External references