# A183116 (b-file synthesized from sequence entry) 0 0 1 1 2 4 3 11 4 30 5 85 6 244 7 715 8 2118 9 6309 10 18860 11 56475 12 169262 13 507541 14 1522244 15 4566155 16 13697590 17 41091429 18 123272252 19 369813659 20 1109436254