These files contain minimal finite automata that compute the nth Motzkin number modulo various prime powers. In particular, they show that no Motzkin number is divisible by 23, 52, 132, 312, or 372. They were computed with my package IntegerSequences. See my paper with Reem Yassawi for more details.

These automata can be also computed by another method, described in my paper with Doron Zeilberger and implemented in his package AutoSquared.