A026577 T(2n-1,n-1), T given by A026568.
1, 2, 8, 34, 121, 606, 2155, 11306, 40717, 217666, 792351, 4280046, 15703156, 85410872, 315180458, 1722900242, 6385672193, 35040356022
Offset: 1
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