2 in one weekend! I'm on fire ha! Here's another squares game using sequences. The idea is that 2 people play against each other by choosing a line they want to cross out following the regular rules for the squares game. By finding the nth term shown in the box at the bottom they can ensure they have the right answer and cross through their line.
Hope you enjoy it! :-) Not a bad way of getting a pair to answer 25 questions on sequences!