97026domain: NAppears in sequencesFirst Hadamard-Sylvester matrix self -similar matrix based on the Padovan/ Minimal Pisot 3 X 3 matrix as an 9 X 9 matrix: Characteristic Polynomial:1 - x - x^3 - x^4 - x^5 + 3 x^6 + 2 x^7 - x^9.at n=18A121230a(n) = 3*(9*n - 1)*(3*n - 2).at n=35A277985