# A164741 (b-file synthesized from sequence entry) 0 1 1 6 2 30 3 150 4 750 5 3750 6 18750 7 93750 8 468735 9 2343600 10 11717640 11 58586400 12 292923000 13 1464570000 14 7322625000 15 36612000000 16 183054375210 17 915243753000 18 4576078154040 19 22879687737000 20 114394923627000 21 571957043385000