# A050180 (b-file synthesized from sequence entry) 1 1 2 3 3 12 4 24 5 42 6 60 7 132 8 303 9 312 10 450 11 564 12 1236 13 1419 14 2952 15 10098 16 12060 17 13848 18 17229 19 22356 20 37896 21 251904