1²+2²+3²+……+n²=1/6×n(n+1)(2n+1)
① 1²+……+6²=1/6×6×7×13=91
② 1²+……+30²=1/6×30×31×61=9455
③ 10²+……+24²=(1²+……+24²)-(1²+9²)=1/6×24×25×49-1/6×9×10×19=4900-285=4615
1²+2²+3²+……+n²=1/6×n(n+1)(2n+1)
① 1²+……+6²=1/6×6×7×13=91
② 1²+……+30²=1/6×30×31×61=9455
③ 10²+……+24²=(1²+……+24²)-(1²+9²)=1/6×24×25×49-1/6×9×10×19=4900-285=4615