Number of compositions of n such that no two adjacent parts are equal, and the first part is not equal to the last part if there is more than one part.

A212322

Number of compositions of n such that no two adjacent parts are equal, and the first part is not equal to the last part if there is more than one part.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =3a(4) =3a(5) =5a(6) =13a(7) =17a(8) =29a(9) =55a(10) =99a(11) =161a(12) =293a(13) =507a(14) =881a(15) =1561a(16) =2727a(17) =4743a(18) =8337a(19) =14579a(20) =25497a(21) =44675a(22) =78173a(23) =136753a(24) =239437a(25) =419077a(26) =733377a(27) =1283701a(28) =2246823a(29) =3932249

External references