(1)∵n为正整数,
∴OA n 2=(
n-1 ) 2+1,S n=
n
2 ,
(2)∵OA n 2=(
n-1 ) 2+1,S n=
n
2 ,
∴OA 10 2=(
9 ) 2+1=10,
∴OA 10=
10 ,
(3)∵S n=
n
2 ,
∴S 1 2+S 2 2+S 3 2+…+S 10 2=(
1
2 ) 2+(
2
2 ) 2+(
3
2 ) 2+…+(
9
2 ) 2+ (
10
2 ) 2 =
55
4
(1)∵n为正整数,
∴OA n 2=(
n-1 ) 2+1,S n=
n
2 ,
(2)∵OA n 2=(
n-1 ) 2+1,S n=
n
2 ,
∴OA 10 2=(
9 ) 2+1=10,
∴OA 10=
10 ,
(3)∵S n=
n
2 ,
∴S 1 2+S 2 2+S 3 2+…+S 10 2=(
1
2 ) 2+(
2
2 ) 2+(
3
2 ) 2+…+(
9
2 ) 2+ (
10
2 ) 2 =
55
4