Number of pieces after a sheet of paper is folded n times and cut diagonally.

Terms

a(0) =2a(1) =3a(2) =5a(3) =8a(4) =13a(5) =23a(6) =41a(7) =77a(8) =145a(9) =281a(10) =545a(11) =1073a(12) =2113a(13) =4193a(14) =8321a(15) =16577a(16) =33025a(17) =65921a(18) =131585a(19) =262913a(20) =525313a(21) =1050113a(22) =2099201a(23) =4197377a(24) =8392705a(25) =16783361a(26) =33562625a(27) =67121153a(28) =134234113a(29) =268460033