A095386 Largest prime factor of peak values of 3x+1 trajectory started at n.

2, 2, 2, 2, 2, 13, 2, 13, 2, 13, 2, 5, 13, 5, 2, 13, 13, 11, 5, 2, 13, 5, 3, 11, 5, 577, 13, 11, 5, 577, 2, 5, 13, 5, 13, 7, 11, 19, 5, 577, 2, 7, 13, 17, 5, 577, 3, 37, 11, 29, 13, 5, 577, 577, 7, 7, 11, 19, 5, 23, 577, 577, 2, 7, 5, 19, 17, 13, 5, 577, 3, 577, 7, 17, 11, 29, 19, 101, 5