OA22=(
OA32=12+(
OA42=12+(
(1)请用含有n(n是正整数)的等式表示上述变规律:OAn2=______;Sn=______.
(2)求出OA10的长.
(3)若一个三角形的面积是
(4)求出S12+S22+S32+…+S102的值.