# A149037 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 10 4 35 5 128 6 507 7 2018 8 8233 9 34330 10 144621 11 616132 12 2653433 13 11506566 14 50254573 15 220854412 16 975469382 17 4328974934 18 19292389001 19 86294255900 20 387314440619 21 1743745017299 22 7872524977741 23 35634378681771 24 161678959915454 25 735169254989379 26 3349694058675870 27 15291239270252546