{n+1}{n+2}{n+3}{n+4}+1=[{n+1}{n+4}][{n+2}{n+3}]+1=[{n^2+5n+4}][{n^2+5n+6}]+1=[{n^2+5n+4}][{n^2+5n+4+2}]+1=[{n^2+5n+4}]^2+2*[{n^2+5n+4}]*1+1=[{n^2+5n+4}+1]^2={n^2+5n+5}^2
