t
n
n+2
n
(2) (k²+5k)
11
1
k=1
n
El
/on(n+1)(n+1)+5. い(ひかり)
= (ml)(21)+n(n+1)
=
u
6
//on(n+1){(n+1)=153
(3) (i +3i+1)
1
n
ziz +37
i=1
人口
=//on(n+1)(n+1)+3/(n+1)
〃
flute) (2n+1)+ In (n+1)+n
6
=(x+1){(2x+1)+9+}
n
(4) Z (2k+1)²
=
k=1
=(441)
n
K=1
n
+21
4. f(n+1)(+1) + 4 = n(nel) +
±n (n+1)(n+1)+ £n (n+1)+n
4
6
(+1){(n+1)+3+}
(5) (k-1)(2k+3)
k=1
if n
= 1/an(n+1)(2n+16)
(n+1)(n+8) 4
12 n(n+1)(3n+4)
3
