A036674 G.f.: A(x) = (1/2)*x*(B(x)^2+B(x^2)), where B(x) = g.f. for A000600.
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 4, 10, 30, 78, 221, 590, 1619, 4366, 11858, 32029, 86744, 234487, 634630, 1717133, 4649560, 12593571, 34133104, 92560816, 251166524, 681957954, 1852822658, 5037107601, 13702625939, 37298828081
Offset: 0