# A148684 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 7 4 22 5 66 6 227 7 768 8 2753 9 9971 10 37279 11 140691 12 540745 13 2103349 14 8280868 15 32903529 16 131904514 17 533181995 18 2170444180 19 8892860703 20 36646858917 21 151866209400 22 632446821837 23 2645948283877 24 11116175518696 25 46888154457285 26 198501876181794 27 843238066609291 28 3593501683668228