# A037711 (b-file synthesized from sequence entry) 1 1 2 9 3 56 4 336 5 2017 6 12105 7 72632 8 435792 9 2614753 10 15688521 11 94131128 12 564786768 13 3388720609 14 20332323657 15 121993941944 16 731963651664 17 4391781909985 18 26350691459913 19 158104148759480 20 948624892556880 21 5691749355341281