# A129532 (b-file synthesized from sequence entry) 0 0 1 0 2 6 3 72 4 576 5 3840 6 23040 7 129024 8 688128 9 3538944 10 17694720 11 86507520 12 415236096 13 1962934272 14 9160359936 15 42278584320 16 193273528320 17 876173328384 18 3942779977728 19 17626545782784 20 78340203479040 21 346346162749440