A026667 a(n) = T(n,0) + T(n,1) + ... + T(n,[ n/2 ]), T given by A026659.

1, 1, 3, 5, 14, 21, 55, 98, 255, 421, 1047, 1939, 4851, 8393, 20265, 38423, 93728, 166999, 395317, 761724, 1824934, 3319575, 7745123, 15103234, 35691596, 65946113, 152151529, 299476048, 700050056, 1309537115, 2994340063