Number of compositions of n with all adjacent parts (x, y) satisfying x > 2y or y = 2x.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =2a(6) =4a(7) =6a(8) =5a(9) =6a(10) =8a(11) =10a(12) =12a(13) =15a(14) =19a(15) =22a(16) =25a(17) =28a(18) =37a(19) =41a(20) =46a(21) =62a(22) =72a(23) =79a(24) =95a(25) =113a(26) =123a(27) =144a(28) =176a(29) =200