1073790977domain: NAppears in sequencesa(n) = 4^(n+1) + 3*2^n + 1.at n=15A036562Number of pieces after a sheet of paper is folded n times and cut diagonally.at n=31A257418a(0)=3; for n > 0, a(n) = 2^(2*n) + 3*2^(n-1) + 1.at n=15A343176