# A063768 (b-file synthesized from sequence entry) 0 2 1 11 2 67 3 521 4 4099 5 32771 6 262147 7 2097169 8 16777259 9 134217757 10 1073741827 11 8589934609 12 68719476767 13 549755813911 14 4398046511119 15 35184372088891 16 281474976710677 17 2251799813685269 18 18014398509482143 19 144115188075855881