Mathematical formula

${(3n+1)}^2=[[10\cdot {[\frac{1}{3}\cdot \left(3n\right)]}^2]-{[\frac{1}{3}\cdot \left(3n\right)]}^2]+3n+(3n+1)$

(3n+1)²=((10·⅓·(3n)²)-(3n)²)+3n+(3n+1) no such category found: mathematical formula