# A138315 (b-file synthesized from sequence entry) 0 1 1 1 2 1 3 3 4 9 5 45 6 225 7 3015 8 22545 9 473625 10 4637025 11 191508075 12 2288273625 13 123786785925 14 1735168572225 15 276775700288175 16 4433024011291425 17 510439906229029425 18 9196849128341801025 19 3123191121957643317075