给定 n,k,{ak}n,k,{a_k}n,k,{ak},设 : G(x)=∑i=0n(1)i(ni)(F(x)+ni)nG(x) = sum _{i = 0} ^n (-1) ^ i dbinom{n}{i} (F(x) + n - i) ^ nG(x)=∑i=0n(1)i(in)(F(x)+ni)n 其中 F(x)=∑i=0kaixi.F(x) = sum _{i = 0} ^ k a_i
给定 n,k,{ak}n,k,{a_k}n,k,{ak},设 : G(x)=∑i=0n(−1)i(ni)(F(x)+n−i)nG(x) = sum _{i = 0} ^n (-1) ^ i dbinom{n}{i} (F(x) + n - i) ^ nG(x)=∑i=0n(−1)i(in)(F(x)+n−i)n 其中 F(x)=∑i=0kaixi.F(x) = sum _{i = 0} ^ k a_i x ^ i.F(x)=∑i=0kaixi. 求 G(x)G(x)G(x) 各项系数之和对 998244353998244353998244353 取模的值。
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