A026889 T(2n+1,n+3), T given by A026769.
1, 7, 37, 178, 825, 3774, 17250, 79326, 368516, 1733597, 8268603, 40003178, 196273837, 976066486, 4915503146, 25042730042, 128927697340, 670023585820, 3511276691660, 18537816521102, 98514404946264, 526575421631986
Offset: 2