A048115 (1/2)*Sum{T(n,i): i=0,1,...,n}, where T is given by A048113.

1, 1, 2, 4, 6, 12, 24, 42, 84, 168, 312, 624, 1248, 2388, 4776, 9552, 18576, 37152, 74304, 145884, 291768, 583536, 1152456, 2304912, 4609824, 9138888, 18277776, 36555552, 72654552, 145309104, 290618208, 578607912