# A011946 (b-file synthesized from sequence entry) 1 1 2 2 3 3 4 8 5 15 6 30 7 63 8 128 9 252 10 510 11 1023 12 2040 13 4095 14 8190 15 16365 16 32768 17 65535 18 131040 19 262143 20 524280 21 1048509 22 2097150 23 4194303 24 8388480 25 16777200 26 33554430 27 67108608 28 134217720 29 268435455 30 536870370 31 1073741823 32 2147483648 33 4294966269 34 8589934590