# A065938 (b-file synthesized from sequence entry) 1 1 2 6 3 14 4 7 5 120 6 248 7 16160 8 1019 9 127 10 32640 11 65408 12 16373 13 8386032 14 4194056 15 4194239 16 32767 17 2147450880 18 4294934528 19 4611672824287851743 20 268435343 21 8796091842564 22 1125899889968159 23 70368744112268 24 70368744161279