# A058408 (b-file synthesized from sequence entry) 0 1 1 4 2 26 3 129 4 546 5 2010 6 6615 7 19650 8 53790 9 137035 10 328262 11 745078 12 1613072 13 3348198 14 6693822 15 12937656 16 24253200 17 44219610 18 78604130 19 136511100 20 232054284