Congruences modulo powers of 5 for two restricted bipartitions

Let B5(n)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$B_{5}(n)$$\end{document} denote the number of 5-regular bipartitions of n. We establish some Ramanujan-type congruences like B5(4n+3)≡0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$B_{5}(4n+3) \equiv 0$$\end{document} (mod 5) and many infinite families of congruences for B5(n)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$B_{5}(n)$$\end{document} modulo higher powers of 5 such as B552k-1n+2·52k-1-13≡0(mod5k).\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\begin{aligned} B_{5}\left( 5^{2k-1}n+\frac{2\cdot 5^{2k-1}-1}{3}\right) \equiv 0 \pmod {5^k}. \end{aligned}$$\end{document}We also apply the same method to obtain some similar results for another type of bipartition function. Meanwhile, we give a new interesting interlinked q-series identity related with Rogers–Ramanujan continued fraction, which answers a question of M. Hirschhorn.