# A004735 (b-file synthesized from sequence entry) 1 1 2 3 3 4 4 15 5 8 6 35 7 64 8 315 9 128 10 693 11 512 12 3003 13 1024 14 6435 15 16384 16 109395 17 32768 18 230945 19 131072 20 969969 21 262144 22 2028117 23 2097152 24 16900975 25 4194304 26 35102025 27 16777216 28 145422675 29 33554432