找規律:1.5,4.5,13.5,(),121.5…… 1,5,9,13,……第10個數是()

找規律:1.5,4.5,13.5,(),121.5…… 1,5,9,13,……第10個數是()

1.5,4.5,13.5,40.5121.5
1,5,9,13,17,21,25,29,33,37