Triangle, read by rows, of Lambert's denominator polynomials related to convergents of tan(x).

Terms

a(0) =1a(1) =1a(2) =0a(3) =3a(4) =0a(5) =-1a(6) =15a(7) =0a(8) =-6a(9) =0a(10) =105a(11) =0a(12) =-45a(13) =0a(14) =1a(15) =945a(16) =0a(17) =-420a(18) =0a(19) =15a(20) =0a(21) =10395a(22) =0a(23) =-4725a(24) =0a(25) =210a(26) =0a(27) =-1a(28) =135135a(29) =0