241515domain: NAppears in sequencesTrajectory of 1 under map n->17n+1 if n odd, n->n/2 if n even.at n=28A033965Number of 4-ary rooted trees with n nodes and height at most 4.at n=34A036609Number of 4-ary rooted trees with n nodes and height exactly 4.at n=34A036628