'------------------------------------------------
'***** 1 *****
Option Explicit              '変数の宣言を強制

Sub main()
    Const LIMIT = 1000

    Dim n As Long, count As Long, r As Long
    
    count = 0
    For n = 1 To LIMIT
        r = i_sqr(2 * n + 1)
        If (r * r = 2 * n + 1) Then
            count = count + 1
            Cells(count, 1).Value = r
            Cells(count, 2).Value = n
            Cells(count, 3).Value = n + 1
        End If
    Next n

End Sub

Function i_sqr(n As Long) As Long    '平方根の整数部のみを返す関数
    Dim i As Long, count As Long, sum As Long
        
    count = 0
    sum = 0
    i = 1
    Do While sum < n
        i = i + 2
        sum = sum + i
        count = count + 1
    Loop
    i_sqr = count
    
End Function
'------------------------------------------------
'***** 2 *****
Option Explicit        '変数宣言を強制

Sub main1()            '奇数の自乗を、差が１の２数に分割する方法
    Const LIMIT = 100

    Dim n As Long, count As Long, tmp As Long

    count = 0
    For n = 3 To LIMIT Step 2
        tmp = n * n
        count = count + 1
        Cells(count, 1).Value = n
        Cells(count, 2).Value = tmp \ 2         '「\」は整数除算の演算子。商の整数部分のみを返す。
        Cells(count, 3).Value = tmp \ 2 + 1
    Next n

End Sub
'------------------------------------------------
'***** 3 *****
Option Explicit        '変数宣言を強制

Sub main2()
    Const LIMIT = 100

    Dim n As Long, count As Long

    count = 0
    For n = 1 To LIMIT
        count = count + 1
        Cells(count, 1).Value = 2 * n + 1
        Cells(count, 2).Value = 2 * n * n + 2 * n
        Cells(count, 3).Value = 2 * n * n + 2 * n + 1
    Next n

End Sub
'------------------------------------------------