Number of pairs of adjacent equal parts in all gap-free compositions of n.

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =6a(5) =12a(6) =26a(7) =56a(8) =124a(9) =266a(10) =563a(11) =1204a(12) =2573a(13) =5468a(14) =11559a(15) =24370a(16) =51281a(17) =107720a(18) =225867a(19) =472660a(20) =987378a(21) =2059180a(22) =4287932a(23) =8916624a(24) =18517398a(25) =38406486a(26) =79563118a(27) =164636582a(28) =340308519a(29) =702713844