# A068195 (b-file synthesized from sequence entry) 1 1 2 3 3 6 4 10 5 28 6 136 7 496 8 8128 9 32896 10 33550336 11 2147516416 12 8589869056 13 137438691328 14 2305843008139952128 15 2658455991569831744654692615953842176