# A124384 (b-file synthesized from sequence entry) 0 1 1 2 2 4 3 10 4 30 5 110 6 494 7 2734 8 18734 9 159278 10 1685550 11 22268974 12 367653934 13 7597868078 14 196929315886 15 6402998805550 16 261393582040110 17 13416320169124910 18 865576139256079406 19 70227589169019724846 20 7172766017169503134766 21 921829147482582383174702