# A165929 (b-file synthesized from sequence entry) 1 1 2 1 3 3 4 6 5 12 6 24 7 48 8 120 9 264 10 480 11 1104 12 2064 13 4128 14 10752 15 19320 16 38328 17 91992 18 170016 19 369600 20 745560 21 1854720 22 3845760 23 7765296 24 14990520 25 29910120 26 59856720 27 119710416 28 298755600 29 667297320 30 1446528360 31 4011171840