# A166456 (b-file synthesized from sequence entry) 0 1 1 2 2 6 3 12 4 30 5 60 6 124 7 248 8 510 9 1020 10 2044 11 4088 12 8188 13 16376 14 32760 15 65520 16 131070 17 262140 18 524284 19 1048568 20 2097148 21 4194296 22 8388600 23 16777200 24 33554428 25 67108856 26 134217720 27 268435440 28 536870904 29 1073741808 30 2147483632 31 4294967264 32 8589934590 33 17179869180