# A035077 (b-file synthesized from sequence entry) 0 1 1 6 2 15 3 70 4 105 5 2310 6 5005 7 30030 8 255255 9 3233230 10 969969 11 44618574 12 37182145 13 223092870 14 3234846615 15 66853496710 16 100280245065 17 200560490130 18 1236789689135 19 7420738134810 20 30425026352721