# A001229 (b-file synthesized from sequence entry) 1 1 2 2 3 8 4 12 5 128 6 240 7 720 8 6912 9 32768 10 142560 11 712800 12 1140480 13 1190400 14 3345408 15 3571200 16 5702400 17 14859936 18 29719872 19 50319360 20 118879488 21 2147483648 22 3889036800 23 4389396480 24 21946982400 25 47416320000 26 92177326080 27 133145026560 28 331914240000 29 460886630400 30 665725132800