# A148083 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 4 4 9 5 24 6 68 7 204 8 635 9 2048 10 6684 11 22581 12 77989 13 271706 14 968228 15 3500939 16 12729468 17 47024807 18 175664979 19 658360378 20 2498042454 21 9560670342 22 36669158456 23 142032179940 24 553961114253 25 2163565785558 26 8518522634671 27 33731910890175 28 133687274886976 29 533438652268653 30 2138794101079053