LegendreP[n, x]
LegendreP[n, m, x]
LegendreP[4, x]
LegendreP[5/2, 1.5]
LegendreP[1.75, 1.4, 0.53]
LegendreP[1.6, 3.1, 1.5]
LegendreP can be used to draw generalized Lissajous figures:
LegendreP
ParametricPlot[ {LegendreP[7, x], LegendreP[5, x]}, {x, -1, 1}]