Summary: We present techniques for obtaining a generating function for the diagonal $T_{2n,n}$ of the triangle formed from the coefficients of a generating function $G(x)$ raised to the power $k$. We obtain some relations between central coefficients and coefficients of the diagonal $T_{2n,n}$, and we also give some examples.

05A15, 11B75, 05A10

generating function, triangle, diagonal, central coefficient, composita