# A199163 (b-file synthesized from sequence entry) 0 1 1 2 2 10 3 56 4 404 5 3272 6 30688 7 316304 8 3609656 9 44624624 10 597131600 11 8555752064 12 130941724064 13 2127005759296 14 36577172243776 15 663151898857856 16 12646212723268576 17 252922802230850496 18 5294480128736395456 19 115747660924409952512 20 2638244919080808844544