import sys
input = sys.stdin.readline

from functools import lru_cache
@lru_cache(maxsize=None)
def f(n,k):
    if n==1:
        if k==1:
            return 2
        else:
            return 0
    if n==2:
        if k==1:
            return 5
        if k==2:
            return 2
        if k==3:
            return 1
        return 0

    if k==1:
        ANS=pow(2,pow(2,n,mod-1)-2,mod)
    else:
        ANS=0

    for i in range(k+1):
        ANS+=f(n-1,i+1)*f(n-1,k-i)
        ANS%=mod

    return ANS
        

mod=998244353

T=int(input())
for tests in range(T):
    N,K=map(int,input().split())

    ANS=f(N,K)

    print(ANS%mod)