A001795 — Coefficient of P_0(x) in the Legendre expansion of x^n
A001796 — Coefficient of P_1(x) in the Legendre expansion of x^n
A001797 — Coefficient of P_2(x) in the Legendre expansion of x^n
A001798 — Coefficient of P_3(x) in the Legendre expansion of x^n
A001799 — Coefficient of P_4(x) in the Legendre expansion of x^n
A006750 — Coefficient of P_5(x) in the Legendre expansion of x^n
x^0 = P_0(x)
x^1 = P_1(x)
x^2 = (P_0(x) + 2 P_2(x))/3
x^3 = (3 P_1(x) + 2 P_3(x))/5
x^4 = (7 P_0(x) + 20 P_2(x) + 8 P_4(x))/35
x^5 = (27 P_1(x) + 28 P_3(x) + 8 P_5(x))/63
x^6 = (33 P_0(x) + 110 P_2(x) + 72 P_4(x) + 16 P_6(x))/231
x^7 = (143 P_1(x) + 182 P_3(x) + 88 P_5(x) + 16 P_7(x))/429
Reading down the columns gives
P_0: 1, 1, 7, 33, ... = A001795
P_1: 1, 3, 27, 143, ... = A001796
P_2: 2, 20, 110, ... = A001797
P_3: 2, 28, 182, ... = A001798
P_4: 8, 72, ... = A001799
P_5: 8, 88, ... = A006750