# A151483 (b-file synthesized from sequence entry) 0 1 1 1 2 4 3 12 4 48 5 192 6 832 7 3712 8 17152 9 81152 10 392192 11 1928192 12 9621504 13 48623616 14 248463360 15 1282031616 16 6672285696 17 34993274880 18 184793432064 19 981947645952 20 5247335399424 21 28185150357504 22 152104870084608 23 824404913160192 24 4486067252101120 25 24501262150008832 26 134274187559698432 27 738200201575006208