Array
(
    [a] => 1
    [c] => 3
    [e] => 5
)
Pairs :
Array
(
    [0] => 6
    [2] => 8
    [4] => 10
    [6] => 12
)
Tableaux d'origine :
Array
(
    [a] => 1
    [b] => 2
    [c] => 3
    [d] => 4
    [e] => 5
)
Array
(
    [0] => 6
    [1] => 7
    [2] => 8
    [3] => 9
    [4] => 10
    [5] => 11
    [6] => 12
)