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

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =3a(5) =1a(6) =16a(7) =16a(8) =6a(9) =1a(10) =125a(11) =125a(12) =50a(13) =10a(14) =1a(15) =1296a(16) =1296a(17) =540a(18) =120a(19) =15a(20) =1a(21) =16807a(22) =16807a(23) =7203a(24) =1715a(25) =245a(26) =21a(27) =1a(28) =262144a(29) =262144