from heapq import *

flowers = [0] * 1000000

heap = []
for b in range(2,17):
    for d in range(1,b):
        heappush(heap, [d, b, d])
for i in range(1,len(flowers)):
    v,b,d = heappop(heap)
    if v != flowers[i-1]:
        flowers[i] = v % 998244353
    heappush(heap, [v*b+d, b, d])

for i in range(1,len(flowers)):
    flowers[i] = (flowers[i] + flowers[i-1]) % 998244353

t = int(input())

for _ in range(t):
    a, b = map(int,input().split())
    print(flowers[b]-flowers[a-1])