User blog comment:DrCeasium/Hyperfactorial notation update/@comment-1605058-20130422164437

Small Veblen ordinal is equal to \(\vartheta(\Omega^\omega)\) in Feferman's theta function or \(\psi(\Omega^{\Omega^\omega})\) in Buchholz's psi function. For large Veblen ordinal replace top \(\omega\) with \(\Omega\). It may be a bit confusing, but different collapsing functions lead to different values of functions.