Sitefinity Template Layout Helpers. Use these in a RadListView to generate you dynamic layout wrappers around your content.

Samples.aspx

<!-- Regular Sample -->
<telerik:RadListView ID="dynamicContentListView" ItemPlaceholderID="ItemsContainer" runat="server" EnableEmbeddedSkins="false" EnableEmbeddedBaseStylesheet="false">
    <LayoutTemplate>
      <div class="sf_cols">
            <asp:PlaceHolder ID="ItemsContainer" runat="server" />
        </div>
    </LayoutTemplate>
    <ItemTemplate>
        <div class='<%# Util.Out(Container) %>'>
            <div class='<%# Util.In(Container) %>'>
              <!-- Content Goes Here -->
            </div>
        </div>
    </ItemTemplate>
</telerik:RadListView> 

<!-- Group Sample -->
    <telerik:RadListView ID="dynamicContentListView" ItemPlaceholderID="ItemsContainer" runat="server" EnableEmbeddedSkins="false" EnableEmbeddedBaseStylesheet="false" GroupPlaceholderID="GroupContainer" GroupItemCount="4">
        <LayoutTemplate>
            <asp:PlaceHolder ID="GroupContainer" runat="server" />
        </LayoutTemplate>
        <GroupTemplate>
            <div class="sf_cols">
                <asp:PlaceHolder ID="ItemsContainer" runat="server" />
            </div>
        </GroupTemplate>
        <ItemTemplate>
          <div class='<%# Util.Out(Container) %>'>
              <div class='<%# Util.In(Container) %>'>
                  <!-- Content Goes Here -->
              </div>
          </div> 
        </ItemTemplate>
    </telerik:RadListView>

SitefinityLayoutHelpers.cs

public static class Util
    {
	public static string Out(RadListViewDataItem item, int colCount = -1)
	{
		return Util.GenerateColumnMath("sf_colsOut sf_{0}cols_{1}_{2}", item, colCount);
	}
	
	public static string In(RadListViewDataItem item, int colCount = -1)
	{
		return Util.GenerateColumnMath("sf_colsIn sf_{0}cols_{1}in_{2}", item, colCount);
	}
	
	public static string GenerateColumnMath(string stringFormat, RadListViewDataItem item, int colCount = -1){
		var total = (colCount != -1) ? colCount : item.OwnerListView.GroupItemCount;
		var index = (item.DataItemIndex + 1);
		
		var size = 100 / total;
		

		
		//index = index % total + 1;
		while (index > total)
		{
		        index = index - total;
		}
		
		if (total == 3 && index == 2)
		        size = 34;
		
		
		string className = String.Format(stringFormat,total,index,size);
		
		return className;
	}
}