Please, I can't find an element of the subgroup of $A_7$ generated by $a=(1234567)$ and $b=(26)(34)$ with order 4.
If anybody could give me the combination of $a$ and $b$ I need, it would be fantastic. I have tried everything I swear. I have tried to find a matrix of $SL(3,2)$ with order $4$, generated by $[0 1 1, 0 0 1, 1 1 1]$ and $[1 0 1, 0 1 0, 0 0 1]$ and use an isomorphism (other matrices don't work with my isomorphism).