In the 1960's, Dana Scott constructed the domain $D_{\infty}$ which has the property $D_{\infty} \cong D_{\infty}{}^{D_{\infty}}$. Its construction is based on a cumulative hierarchy of infinite sequences. For an exposition of its construction one can read the Stenlund (1972) book, “Combinators, $\lambda$-terms and proof theory". Assume that we know the cardinality of $||D_0|| = d$. Then $D_1 = D_0 {}^{D_0}$, so $||D_1|| = d^d$. $D_2 = D_1{}^{D_1}$, so $||D_2|| = {(d^d)}^{(d^d)} = d^{d^{(d+1)}}$. Is there a way to express $||D_{\infty}||$ in terms of $d$ ?