A033975 Trajectory of 1 under map n->39n+1 if n odd, n->n/2 if n even

1, 40, 20, 10, 5, 196, 98, 49, 1912, 956, 478, 239, 9322, 4661, 181780, 90890, 45445, 1772356, 886178, 443089, 17280472, 8640236, 4320118, 2160059, 84242302, 42121151, 1642724890, 821362445, 32033135356