# A355747 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 4 4 10 5 20 6 58 7 116 8 320 9 772 10 2170 11 4340 12 14112 13 28224 14 78120 15 212004 16 612232 17 1224464 18 3873760 19 7747520 20 24224608 21 64595088 22 175452168 23 350904336