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-k)!*k!), as a triangle of coefficients T(n,k) read by rows.

A322193

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-k)!*k!), as a triangle of coefficients T(n,k) read by rows.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =4a(6) =5a(7) =4a(8) =1a(9) =1a(10) =16a(11) =41a(12) =52a(13) =41a(14) =16a(15) =1a(16) =1a(17) =64a(18) =365a(19) =784a(20) =977a(21) =784a(22) =365a(23) =64a(24) =1a(25) =1a(26) =256a(27) =3281a(28) =12352a(29) =23801

External references