# A069307 (b-file synthesized from sequence entry) 2 21 3 110 4 581 5 3070 6 16227 7 85776 8 453423 9 2396868 10 12670261 11 66977242 12 354053617 13 1871590506 14 9893561055 15 52299127660 16 276462513603 17 1461430140016 18 7725380293233 19 40837737667414 20 215875562691877