1,3,3,5,7,9,13,15(),()相邻奇数差为2,公差为2的等差数列

问题描述:

1,3,3,5,7,9,13,15(),()相邻奇数差为2,公差为2的等差数列

1,3,3,5,7,9,13,15(21),(23)