2乘4乘6乘8加16等于400,4乘6乘8乘10加16等于1936,6乘8乘10乘12加16等于5776,有什么规律用含n的代数式表示

它们都是平方数规律：2n*(2n+2)(2n+4)(2n+6)+16=2[n(n+1)(n+2)(n+3)]+16=16n(n+1)(n+2)(n+3)+16=16[n(n+1)(n+2)(n+3)+1]=16[(n^2+3n)(n^2+3n+2)+1]=16[(n^2+3n)^2+2(n^2+3n)+1]=[4(n^2+3n+1)]^2