#!/bin/ruby
def depth array
  if array.length==0
    return 0
  end
  return Math.log2(array.length).ceil
end

def scramble array
  if array.length<2
    return array
  end
  mid=(array.length)/2
  return [array[mid]]+scramble(array[0..(mid-1)])+scramble(array[(mid+1)..-1])
end
q = gets.strip.to_i
for a0 in (0..q-1)
  n,c = gets.strip.split(' ').map(&:to_i)
  sum=((n-1)*(n))/2
  if c>sum
    puts -1
    next
  end
  flag = false
    # your code goes here
  leftarray=[]
  rightarray=(1..n).to_a
  c=sum-c
  #puts c
  while c>0
    if rightarray.length==0
      puts -1
      flag=true
      break
    end
    if c>=rightarray.length-1
      leftarray << rightarray.delete_at(-1)
      c-=leftarray.length-depth(leftarray)
      #puts c
    else
      newidx=rightarray.length-1-c
      tmp=rightarray[newidx]
      rightarray[newidx]=rightarray[newidx-1]
      rightarray[newidx-1]=tmp
      #rightarray.insert(newidx,rightarray.delete_at(-1))
      c=0
    end
  end
  if flag
    next
  end
  #puts leftarray.length.to_s+ " "+rightarray.length.to_s
  puts (scramble(leftarray)+rightarray).join(" ")
end

#the numbers stored at a specific depth are less than 2*numbers stored at the lower depth