I sold my house. Where to find A1 "Alternative Minimum Tax Deprecation allowed or allowable on prior tax returns" required on "Adjusted Basis of Home Sold Worksheet"?

Yes, AMT depreciation is reported each year for Rental Properties on a supplemental worksheet to Schedule E that is typically included with your entire tax return. You will need only the AMT report for the last tax year that you rented the home. The amount to enter on the Adjusted Basis worksheet is the total of Prior and Current Depreciation.

If you used TurboTax to prepare your taxes last year, look for Form 4562 Alternative Minimum Tax Report (see screenshot below - click to enlarge) This is a TurboTax worksheet and not an IRS form. If you downloaded your entire return as a PDF, the depreciation worksheet usually follows Schedule E.

If you used a professional, review your copy for a record of the asset or for a depreciation report or schedule. If you do not see any of these, contact that preparer for a copy.

Yes, I used TurboTax 2016 to file taxes last year. I printed "2016 Individual Tax Return_Records with all calculation sheets" and I also still have Turbo Tax 2016 installed.

There was no "Form 4562 Alternative Minimum Tax Report" generated and included in the 2016 Turbo Tax Return Records.
 
On Schedule E Worksheet 18a box "Deprecation" is blank. There is no AMT depreciation on Schedule E Worksheet.

On Smart Worksheet for Schedule E Worksheet I see that "E Other Adjustments and preferences" Regular value is blank and AMT value is also blank. Does it mean depreciation is zero?

Yes, if you have no AMT depreciation report and no depreciation on the Schedule E worksheet, you did not take any depreciation for this asset in the past.