JOURNAL OF THE KOREAN MATHEMATICAL SOCIETY, cilt.52, sa.2, ss.333-347, 2015 (SCI-Expanded)
In this paper, by using the modular forms of weight nk (2 <= n is an element of N and k is an element of Z), we construct a formula which generates modular forms of weight 2nk + 4. This formula consist of some known results in [14] and [4]. Moreover, we obtain Fourier expansion of these modular forms. We also give some properties of an operator related to the derivative formula. Finally, by using the function j(4), we obtain the Fourier coefficients of modular forms with weight 4.