Defined Benefit Pension question question, practice, payments, benefit, related

ba736

Dear all,
Would you help me with one of the practice questions related to defined benefit plans?
On p, 184 Volume 2. Scenario 4 it is said that Value at the end of year 5 of the estimated future payments = PV of 13,544.68 for 20 years at 6 per cent = 155,356. I get the concept but I can’t seem to arrive at that number. Could you please help me with that?
Kind regards
Niko