# A020540 (b-file synthesized from sequence entry) 0 4 1 56 2 496 3 4064 4 32704 5 262016 6 2096896 7 16776704 8 134216704 9 1073739776 10 8589930496 11 68719468544 12 549755797504 13 4398046478336 14 35184372023296 15 281474976579584 16 2251799813423104 17 18014398508957696 18 144115188074807296