Number of length n+3 0..2 arrays with no four elements in a row with pattern abba (possibly a=b) and new values 0..2 introduced in 0..2 order.

A243027

Number of length n+3 0..2 arrays with no four elements in a row with pattern abba (possibly a=b) and new values 0..2 introduced in 0..2 order.

Terms

    a(0) =12a(1) =32a(2) =85a(3) =226a(4) =601a(5) =1598a(6) =4249a(7) =11298a(8) =30041a(9) =79878a(10) =212393a(11) =564746a(12) =1501641a(13) =3992814a(14) =10616761a(15) =28229618a(16) =75061625a(17) =199586390a(18) =530693641a(19) =1411096922a(20) =3752060265a(21) =9976604734a(22) =26527463577a(23) =70535652418a(24) =187551977881a(25) =498694535334

External references