A077838 Expansion of (1-x)/(1-3*x-2*x^2-3*x^3).

1, 2, 8, 31, 115, 431, 1616, 6055, 22690, 85028, 318629, 1194013, 4474381, 16767056, 62831969, 235453162, 882324592, 3306376007, 12390136691, 46430135863, 173989808992, 652000108775, 2443270351898, 9155780700220, 34309883130781, 128571021848477