M_{22}.2

L_{3}(4) ≤ L_{3}(4).2_{2}  44 1a^{±} + 21a^{±}  4

Character Numbers: [ 1, 2, 3, 4 ]

S_{1} S_{2} S_{3} S_{4}
χ_{1} 1 1 21 21
χ_{2} 1 −1 21 −21
χ_{3} 1 1 −1 −1
χ_{4} 1 −1 −1  1

Ramanujan Graphs: [ 2, 3, 4 ], [ 2, 4 ], [ 3 ], [ 3, 4 ], [ 4 ]