Expansion of (g/(1 - x*g))^2, where g = 1+x*g^3 is the g.f. of A001764.

A391171

Expansion of (g/(1 - x*g))^2, where g = 1+x*g^3 is the g.f. of A001764.

Terms

    a(0) =1a(1) =4a(2) =16a(3) =70a(4) =332a(5) =1674a(6) =8831a(7) =48192a(8) =269918a(9) =1543038a(10) =8967635a(11) =52827050a(12) =314733791a(13) =1893170136a(14) =11481649248a(15) =70131545106a(16) =431053724184

External references