Triangle of expansions of powers of x in terms of Chebyshev polynomials U_n(x).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =2a(7) =3a(8) =1a(9) =5a(10) =4a(11) =1a(12) =5a(13) =9a(14) =5a(15) =1a(16) =14a(17) =14a(18) =6a(19) =1a(20) =14a(21) =28a(22) =20a(23) =7a(24) =1a(25) =42a(26) =48a(27) =27a(28) =8a(29) =1