title: Recursion code in VBA
body: <p><a href="https://i.stack.imgur.com/9Su01.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9Su01.png" alt="enter image description here"></a></p>
  
  <p>I am trying to run this code to calculate Q(n) at different Tn in the Equation 16.4 in the attached picture.But its not giving me the correct output. I would appreciate any help.  Note: delta1=delta2 =...deltan = dt=1 ( I have taken here ) and further divided S term by 10000 just because in the Equation it is in basis point i.e. 100th part of 1 %.</p>
  
  <pre><code>Function Bootstrap(S As Range, Z As Range, L As Double) As Double
  Dim j As Integer
  Dim a As Variant
  Dim b As Variant
  Dim n As Integer
  Dim Q() As Double
  Dim sum As Double
  Dim P As Double
  Dim dt As Double
  
  n = Application.WorksheetFunction.Max(S.Columns.Count, Z.Columns.Count)
  a = S.Value
  b = Z.Value
  dt = 1
  sum = 0
  ReDim Q(0 To n)
  Q(0) = 1
  
  For j = 1 To n - 1
      P = (b(1, j) * (L * Q(j - 1) - (L + dt * a(1, n) / 10000) * Q(j))) / (b(1, n) * (L + a(1, n) * dt / 10000)) + Q(n - 1) * L / (L + a(1, n) * dt / 10000)
      sum = sum + P
      Q(n) = sum
  Next j
  
  Bootstrap = sum
  End Function
  </code></pre>