a(n) = (2*n)! * [x^(2*n)] cosh(x)^n.

A381459

a(n) = (2*n)! * [x^(2*n)] cosh(x)^n.

Terms

    a(0) =1a(1) =1a(2) =8a(3) =183a(4) =8320a(5) =628805a(6) =71172096a(7) =11266376947

External references