# A052912 (b-file synthesized from sequence entry) 0 1 1 2 2 4 3 10 4 24 5 56 6 132 7 312 8 736 9 1736 10 4096 11 9664 12 22800 13 53792 14 126912 15 299424 16 706432 17 1666688 18 3932224 19 9277312 20 21888000 21 51640448 22 121835520 23 287447040 24 678174976 25 1600020992 26 3774936064 27 8906222080 28 21012486144 29 49574844416