A026870 T(2n,n-4), T given by A026758.
1, 14, 125, 911, 5920, 35785, 205991, 1145389, 6208974, 33019048, 173020608, 896198760, 4599517316, 23431544274, 118650995097, 597852859509, 3000150410123, 15004346987002, 74827169741248, 372278740384010, 1848449139166668
Offset: 4