The 2017 Tax Liability that is shown on line 8 of form 2210 starts with the actual 2017 taxes assessed, then has a number of items added to it and subtracted from it. This means that the number on the 2210 in 2018 might not be found on the 2017 return nor derived from it in a simple fashion.
The formula for the 2017 tax liability entry on the 2018 2210 can be found on page 4 (line 😎 of the 2018 2210 Instructions at https://www.irs.gov/pub/irs-pdf/i2210.pdf. You will see how complex the calculations are.
