New entanglement-assisted quantum MDS codes with length n=q2+15\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n=\frac{q^2+1}{5}$$\end{document}

The entanglement-assisted stabilizer formalism can transform arbitrary classical linear codes into entanglement-assisted quantum error correcting codes. In this work, we construct some new entanglement-assisted quantum maximum distance separable codes with length n=q2+15\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n=\frac{q^2+1}{5}$$\end{document} from cyclic codes. Compared with all the previously known parameters with the same length, all of them have flexible parameters and larger minimum distance.