Triangle T(n,k) generalizing the tangent numbers.

Terms

a(0) =1a(1) =2a(2) =6a(3) =16a(4) =48a(5) =72a(6) =272a(7) =816a(8) =1440a(9) =1440a(10) =7936a(11) =23808a(12) =44352a(13) =57600a(14) =43200a(15) =353792a(16) =1061376a(17) =2027520a(18) =2903040a(19) =3024000a(20) =1814400a(21) =22368256a(22) =67104768a(23) =129964032a(24) =195379200a(25) =232243200a(26) =203212800a(27) =101606400a(28) =1903757312a(29) =5711271936