A088524 Greatest twin prime that does not exceed n (starting at n=3).

3, 3, 5, 5, 7, 7, 7, 7, 11, 11, 13, 13, 13, 13, 17, 17, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 29, 29, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 41, 41, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 59, 59, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 71, 71, 73, 73