Gapplet

Given a sequence g1, ..., gt of permutations, determine the centre of the group G generated by them.

Give a sequence of permutations, 
e.g., [2,3,1,6,4,5], [2,1,4,3,6,5], 
 
 
 
A set of generators of the centre of G written both as products of the generators g1, ..., gt of G and as permutations