Question

vb题：求s的值。s=1+（1+2）+（1+2+3）+（1+2+3+4)+……+（1+2+3+4+……+N）（令N=50）

Answer 1

Private Sub Command1_Click()
Dim N As Integer, S As Double, x As Double
Dim i As Integer, j As Integer

N = Val(InputBox("请输入不大于100的自然数N：", "计算", 50))

S = 0
For i = 1 To N
x = 0

For j = 1 To i
x = x + 1
S = S + x
Next j

Next i
Print "当N=" & N & "时，结果为：" & S

End Sub

Answer 2

N是第N项的值还是就是一个N

Answer 3

input n
s=0:t=0
for i=1 to n
t=t+i
s=s+t
next i
print s