#!/usr/bin/env python
import os
import sys
from io import BytesIO, IOBase
import threading 
from math import cos,sin,pi
 


def main():
    for _ in range(int(input())):
        n,m=map(int,input().split())
        arr=[0]*(n+1)
        arr[0]=-1
        
        gap=n//(m+1)
        ind=1
        d=0
        for i in range(m):
            # print(ind)
            ind+=gap
            if ind >n:
                break
            arr[ind]=1
            d+=1
            ind+=1
        i=d
        if (arr[n]==1 and arr[n-1]==0) :
            arr[n-1]=1
            arr[n]=0  
        # print(i)
        while i<m:
            for j in range(n):
                if i<m and arr[j]==0:
                    arr[j]=1
                    i+=1

        # print(arr)
        ans=0
        prev=0
        for i in range(1,n+1):
            if arr[i]==1:
                # ans+=(i-prev+1)*(n-i)
                ans=ans+(i-prev)*(n-i+1)
                prev=i  
        print(ans)



 
        
        
 
 
        
 
BUFSIZE = 8192
 
 
class FastIO(IOBase):
    newlines = 0
 
    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None
 
    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()
 
    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()
 
    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)
 
 
class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")
 
 
sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")
 
# endregion
 
if __name__ == "__main__":
    main()