134234113domain: NAppears in sequencesa(n) = 2 * (4^n + 2^n) + 1.at n=13A085601Expansion of (1 + 4*x - 6*x^2 - 16*x^3 + 20*x^4)/((1-x)*(1-2*x)*(1+2*x)*(1-2*x^2)).at n=27A171663Number of pieces after a sheet of paper is folded n times and cut diagonally.at n=28A257418a(0)=2; for n > 0, a(n) = 2^(2*n-1) + 2^n + 1.at n=14A343175