# A149364 (b-file synthesized from sequence entry) 0 1 1 1 2 4 3 12 4 44 5 168 6 690 7 2854 8 12137 9 52565 10 230978 11 1027736 12 4618934 13 20940759 14 95652631 15 439609712 16 2032093808 17 9437604683 18 44029824803 19 206186450321 20 969017501835 21 4568147835026 22 21597469460174 23 102372497782333 24 486400762196343 25 2316061651796092 26 11050201383338180 27 52819654295561794