Triangle read by rows: T(n, k) = (2*n + 1)! * [y^(2*k)] [x^(2*n+1)] arctan(sec(x*y)*sinh(x)).
A371688
Triangle read by rows: T(n, k) = (2*n + 1)! * [y^(2*k)] [x^(2*n+1)] arctan(sec(x*y)*sinh(x)).
Terms
- a(0) =1a(1) =-1a(2) =3a(3) =5a(4) =-50a(5) =25a(6) =-61a(7) =1281a(8) =-2135a(9) =427a(10) =1385a(11) =-49860a(12) =174510a(13) =-116340a(14) =12465a(15) =-50521a(16) =2778655a(17) =-16671930a(18) =23340702a(19) =-8335965a(20) =555731a(21) =2702765a(22) =-210815670a(23) =1932476975a(24) =-4637944740a(25) =3478458555a(26) =-772990790a(27) =35135945
External references
- oeis: A371688