from heapq import *
MOD = 998244353
def sqrt(n):
    return n // 10000000000

flowers = [0] * 1000001

heap = []
for b in range(2,17):
    for d in range(1,b):
        heappush(heap, [d, b, d, d])
i = 1
while i < len(flowers):
    v,b,d,m = heappop(heap)
    if m != flowers[i-1]:
        flowers[i] = m
        i+=1
    heappush(heap, [v*b+d, b, d, (m*b+d)%MOD])
    if i % 100000 == 0:
        for j in range(len(heap)):
            heap[j][0] //= sqrt(heap[0][0])

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

t = int(input())

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