# A148668 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 7 4 19 5 60 6 185 7 555 8 1841 9 5956 10 19505 11 66820 12 225634 13 756816 14 2642845 15 9115115 16 31500557 17 111381604 18 390731927 19 1366403748 20 4883389422 21 17318135888 22 61435889157 23 221076079788 24 791460173438 25 2827876747472 26 10242954731014 27 36908672701072 28 132984499210420 29 483857249063680 30 1754050251660429