# A156588 (b-file synthesized from sequence entry) 0 1 1 1 2 1 3 1 4 -1 5 2 6 1 7 -1 8 2 9 6 10 1 11 -1 12 3 13 -12 14 24 15 1 16 -1 17 4 18 -36 19 288 20 120 21 1 22 -1 23 5 24 -80 25 2160 26 -34560 27 720 28 1 29 -1 30 6 31 -150 32 9600 33 -777600 34 24883200 35 5040 36 1 37 -1 38 7 39 -252 40 31500 41 -8064000 42 1959552000 43 -125411328000 44 40320 45 1 46 -1 47 8 48 -392 49 84672 50 -52920000