R 6 2 4 July 8, 2019 16 32 64 128 R 2 4 6 8 U r 6 c i 1 2 4 q R 412 6 2 6 r 2 )- 4 =- 10 R (- 6 )=- 2 3x 4 R 4 6 2 e 6 r 4 2 r 8 3r R 6 - 6 or 4r 2 18 R 2 4r 6 0 R 412 6 2 code de la route R 2 12r 6 4r R )- 2 4 6 6 tetramethyloctane 2 r 6 )+ 3r 4 6 ≤ r 2 4 2r 3 2 r 6 4 3