@echo off
setlocal enabledelayedexpansion

set /a backoff = 1
set /a backoff_max = 1

for /L %%a in (1,1,100) do (
  set /a backoff_max= !backoff_max! *2
  echo !backoff_max!
  set /a backoff= %random% %% !backoff_max!

  echo Waiting !backoff! second...
  choice /N /C:YN /T:!backoff! /D:Y >NUL
)