1720976domain: NAppears in sequencesNumber of distinct values taken by 10^10^...^10 (with n 10's and parentheses inserted in all possible ways).at n=17A145550Number of n X 2 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,1) or (-1,-1) and new values introduced in order 0..2.at n=13A275260