# A007855 (b-file synthesized from sequence entry) 1 1 2 3 3 13 4 63 5 326 6 1769 7 9964 8 57843 9 344203 10 2090470 11 12912988 12 80899801 13 512896540 14 3284651548 15 21217493460 16 138080484819 17 904454380446 18 5958186674879 19 39448465279220 20 262359379484522 21 1751912981641794 22 11741044418866476