# A189420 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 6 4 13 5 12 6 -121 7 -896 8 -4391 9 -10160 10 64491 11 900768 12 6118693 13 16033344 14 -198382609 15 -3101259776 16 -22263439439 17 -23508393728 18 1747001723475 19 24367272291840 20 145393520219965