Triangle of coefficients of certain polynomials (exponents in decreasing order).

Terms

a(0) =1a(1) =2a(2) =1a(3) =5a(4) =5a(5) =1a(6) =30a(7) =30a(8) =10a(9) =1a(10) =272a(11) =272a(12) =102a(13) =17a(14) =1a(15) =3250a(16) =3250a(17) =1300a(18) =260a(19) =26a(20) =1a(21) =47952a(22) =47952a(23) =19980a(24) =4440a(25) =555a(26) =37a(27) =1a(28) =840350a(29) =840350