O157
This paper uses n nature numbers from 1 to n to form a numerical table of twofold maoic square' s necessary condition. It also proves that x>n(n-1) and the numerical table is the sufficient condition of the basic solution.
章长才.双重幻方的一个充分条件[J].土木与环境工程学报(中英文),1993,15(4):