Given a sequence a_{0}, a_{1}, a_{2}, \ldots, a_{n}, let its arithmetic approximant be the arithmetic sequence b_{0}, b_{1}, \ldots, b_{n} that minimizes the quantity \sum_{i=0}^{n}\left(b_{i}-a_{i}\right)^{2}, and denote this quantity the sequence’s anti-arithmeticity. Denote the number of integer sequences whose arithmetic approximant is the sequence 4,8,12,16 and whose anti-arithmeticity is at most 20.