1028506domain: NAppears in sequencesThe number of binary sequences of length n for which all patterns {0,1},{0,0},{1,0},{1,1} appear for the first time. In particular, three of the patterns will have appeared at least once before the (n-1)st digit in the sequence and the remaining pattern appears for the first and only time at positions {n-1,n} in the sequence.at n=25A364685