Number of 1-sided strip polykites with n cells.

Terms

a(0) =1a(1) =2a(2) =5a(3) =11a(4) =25a(5) =55a(6) =121a(7) =268a(8) =584a(9) =1268a(10) =2760a(11) =5995a(12) =13031a(13) =28247a(14) =61137a(15) =132074a(16) =285119a(17) =615190a(18) =1326561a(19) =2858429a(20) =6154567a(21) =13242165