Number of circular compositions of n such that no two adjacent parts are equal.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =3a(5) =6a(6) =7a(7) =11a(8) =18a(9) =29a(10) =42a(11) =73a(12) =111a(13) =183a(14) =299a(15) =491a(16) =796a(17) =1333a(18) =2188a(19) =3652a(20) =6073a(21) =10155a(22) =16959a(23) =28500a(24) =47813a(25) =80508a(26) =135621a(27) =228967a(28) =386749a(29) =654535