Generalized tangent numbers d_(n,4).

Terms

a(0) =272a(1) =24611a(2) =515086a(3) =4456448a(4) =23750912a(5) =93241002a(6) =296327464a(7) =806453248a(8) =1951153920a(9) =4300685074a(10) =8787223186a(11) =16878338048a(12) =30768878848a(13) =53624926972a(14) =89982082488a(15) =146028888064a(16) =230022888960a(17) =353194774434a(18) =529896144586