# A052664 (b-file synthesized from sequence entry) 0 1 1 1 2 10 3 60 4 768 5 9480 6 161280 7 2968560 8 65036160 9 1568004480 10 42507763200 11 1259454873600 12 40850693452800 13 1432712945664000 14 54168492771993600 15 2193096759549696000 16 94738664609132544000 17 4347659200973856768000