T(n,k) an additive decomposition of the signed tangent number (triangle read by rows).

Terms

a(0) =1a(1) =2a(2) =-1a(3) =4a(4) =-5a(5) =1a(6) =8a(7) =-19a(8) =9a(9) =0a(10) =16a(11) =-65a(12) =55a(13) =0a(14) =-6a(15) =32a(16) =-211a(17) =285a(18) =0a(19) =-120a(20) =30a(21) =64a(22) =-665a(23) =1351a(24) =0a(25) =-1470a(26) =810a(27) =-90a(28) =128a(29) =-2059