Triangle of coefficients of Legendre polynomials P_n (x).

Terms

a(0) =1a(1) =1a(2) =-1a(3) =3a(4) =-3a(5) =5a(6) =3a(7) =-30a(8) =35a(9) =15a(10) =-70a(11) =63a(12) =-5a(13) =105a(14) =-315a(15) =231a(16) =-35a(17) =315a(18) =-693a(19) =429a(20) =35a(21) =-1260a(22) =6930a(23) =-12012a(24) =6435a(25) =315a(26) =-4620a(27) =18018a(28) =-25740a(29) =12155