# A135632 (b-file synthesized from sequence entry) 1 2 2 4 3 6 4 8 5 30 6 32 7 126 8 128 9 8190 10 8192 11 131070 12 131072 13 524286 14 524288 15 2147483646 16 2147483648 17 2305843009213693950 18 2305843009213693952 19 618970019642690137449562110 20 618970019642690137449562112