179557domain: NAppears in sequencesa(n) = 3600*n^2 - 6751*n + 3165.at n=7A157824a(n) is the number of white and black stones lying in a circle; starting with place 1, the first a(n) steps of length 5 give the places of white stones. Beginning with last place, the next a(n) steps give the places of black stones.at n=13A206602