# A108557 (b-file synthesized from sequence entry) 0 1 1 3 2 9 3 63 4 433 5 2823 6 17657 7 107439 8 642529 9 3802167 10 22357097 11 130970271 12 765564049 13 4469342439 14 26073165401 15 152043343119 16 886424978881 17 5167271805207 18 30119654732489 19 175558462395135 20 1023255914549617