length 2: 12, 21
length 3: 123, 132, 213, 231, 312, 321
length 4: 1234, 1324, 1342, 1423, 1432, 2134, 2143, 2314, 2413, 2431, 3124, 3142, 3214, 3241, 3412, 3421, 4123, 4132, 4213, 4231, 4312, 4321
length 5: 12345, 13245, 13425, 14235, 14325, 14352, 14523, 14532, 15234, 15324, 15342, 15423, 15432, 21345, 21435, 21453, 21534, 21543, 23145, 24135, 24153, 24315, 25134, 25143, 25314, 25413, 25431, 31245, 31425, 31524, 31542, 32145, 32154, 32415, 32514, 32541, 34125, 34215, 35124, 35142, 35214, 35241, 35412, 35421, 41235, 41325, 41352, 41523, 41532, 42135, 42153, 42315, 42513, 42531, 43125, 43152, 43215, 43251, 43512, 43521, 45123, 45132, 45213, 45231, 45312, 45321, 51234, 51324, 51342, 51423, 51432, 52134, 52143, 52314, 52413, 52431, 53124, 53142, 53214, 53241, 53412, 53421, 54123, 54132, 54213, 54231, 54312, 54321
$\mathcal{A}$ = Av(1243, 2341)