# A001665 (b-file synthesized from sequence entry) 0 1 1 4 2 12 3 32 4 88 5 240 6 652 7 1744 8 4616 9 12208 10 32328 11 85408 12 224640 13 589024 14 1542944 15 4039256 16 10560552 17 27567488 18 71878068 19 187262944 20 487526944 21 1268269160 22 3296832292 23 8564411120 24 22235825104 25 57701041072 26 149657337872 27 387978891176 28 1005378745536 29 2604222063144 30 6743181213712 31 17454178002264