Number of words of length n over the alphabet {0,1,2} that contain the substring 12 but not the substring 01.

A335551

Number of words of length n over the alphabet {0,1,2} that contain the substring 12 but not the substring 01.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =5a(4) =18a(5) =58a(6) =177a(7) =522a(8) =1503a(9) =4252a(10) =11869a(11) =32787a(12) =89821a(13) =244415a(14) =661415a(15) =1781654a(16) =4780776a(17) =12786704a(18) =34104792a(19) =90749209a(20) =240982564a(21) =638800052a(22) =1690764378a(23) =4469170031a(24) =11799684559a(25) =31122693066a(26) =82016622160a(27) =215969175981a(28) =568313267862

External references