247716domain: NAppears in sequencesNumber of terms in 6th derivative of a function composed with itself n times.at n=26A022816Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 2 5 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 2 5 6 or 7.at n=10A252417