I'm solving some problem which is related to permutations and differences between adjacent elements in them.
For permutation (1, 2, 3, 4) the differences I'm talking about would be (+1, +1, +1)
For permutation (2, 3, 4, 1) the differences are (+1, +1, -3).
Basically it's an array ($a_1$-$a_o$, $a_2$-$a_1$, ..., $a_n$-$a_{n-1}$)
Is there a proper name for this type of mathematical object?
My English is not very good (especially when it comes to math).
Thank you