# A137784 (b-file synthesized from sequence entry) 1 2 2 -3 3 18 4 -44 5 -72 6 216 7 360 8 -1980 9 -1620 10 3240 11 7176 12 25920 13 -71280 14 -38880 15 58320 16 -151200 17 753480 18 1360800 19 -2494800 20 -1020600 21 1224720 22 -3587520 23 -21772800 24 54250560 25 65318400 26 -89812800 27 -29393280 28 29393280 29 152409600 30 -678041280 31 -2057529600 32 3417785280 33 3086294400