  In this article, we establish an average behaviour of the normalised Fourier
coefficients of the Hecke eigenforms supported at the integers represented by
any primitive integral positive definite binary quadratic form of fixed
discriminant $D < 0$ when the class number $h(D) = 1$.
  We also obtain a quantitative result for the number of sign changes of the
sequence of the normalised Fourier coefficients $\lambda_{f}(n)$ of the Hecke
eigenforms $f$ where $n$ is represented by any primitive integral positive
definite binary quadratic form of fixed discriminant $D < 0$ when the class
number $h(D) = 1$ in the interval $(x,2x]$, for sufficiently large $x$.
