# A104670 (b-file synthesized from sequence entry) 0 1 1 24 2 216 3 1200 4 4950 5 16632 6 48048 7 123552 8 289575 9 629200 10 1283568 11 2482272 12 4585308 13 8139600 14 13953600 15 23193984 16 37509021 17 59183784 18 91333000 19 138138000 20 205134930 21 299562120 22 430775280 23 610740000 24 854611875 25 1181415456 26 1614834144 27 2184124096 28 2925166200