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) =1a(4) =3a(5) =4a(6) =4a(7) =7a(8) =12a(9) =17a(10) =23a(11) =34a(12) =51a(13) =75a(14) =111a(15) =164a(16) =239a(17) =350a(18) =520a(19) =767a(20) =1123a(21) =1652a(22) =2439a(23) =3587a(24) =5263a(25) =7745a(26) =11411a(27) =16789a(28) =24695a(29) =36347