a(n) = coefficient of x^n in the n-th iteration (n-fold self-composition) of the g.f. of squares (A000290).

A302356

a(n) = coefficient of x^n in the n-th iteration (n-fold self-composition) of the g.f. of squares (A000290).

Terms

    a(0) =1a(1) =8a(2) =123a(3) =3064a(4) =107355a(5) =4880896a(6) =273564907a(7) =18252720536

External references