256124504064
domain: N
Appears in sequences
- E.g.f.: C(x,y) = cosh(x)*cosh(y) / (1 - sinh(x)*sinh(y)), where C(x,y) = Sum_{n>=0} Sum_{k=0..2*n} T(n,k) * x^(2*n-k)*y^k/(2*n)!, as a triangle of coefficients T(n,k) read by rows.at n=56A322621
- a(n) = [x^n*y^n/(2*n)!] = (cosh(x)*cosh(y) + sinh(x) + sinh(y)) / (1 - sinh(x)*sinh(y)), for n >= 0.at n=7A322624