# A235359 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 12 4 72 5 768 6 7776 7 118656 8 1696896 9 33623424 10 622245888 11 15149680128 12 344372041728 13 9939463852032 14 268073031942144 15 8944566120382464 16 279256558618312704 17 10572693702605438976 18 375117006060927516672 19 15884838808477768876032 20 631358485413914656899072