Find .
We have to find the coefficient of $\displaystyle x^{1996}$ in the left member.
The powers of x in the left member are of the form $\displaystyle x^{\displaystyle 3^{k_1}+3^{k_2}+\ldots+3^{k_l}}=x^{3p}$
But 1996 is not divisible to 3. So the coefficient is 0.