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.
A322621
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.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =1a(4) =1a(5) =16a(6) =30a(7) =16a(8) =1a(9) =1a(10) =96a(11) =615a(12) =1040a(13) =615a(14) =96a(15) =1a(16) =1a(17) =512a(18) =10220a(19) =43904a(20) =68390a(21) =43904a(22) =10220a(23) =512a(24) =1a(25) =1a(26) =2560a(27) =147645a(28) =1482240a(29) =4998210
External references
- oeis: A322621