Number of length-n 0..2 arrays with no repeated value differing from the previous repeated value by plus or minus one modulo 2+1.

A269684

Number of length-n 0..2 arrays with no repeated value differing from the previous repeated value by plus or minus one modulo 2+1.

Terms

    a(0) =3a(1) =9a(2) =27a(3) =75a(4) =201a(5) =525a(6) =1347a(7) =3411a(8) =8553a(9) =21285a(10) =52659a(11) =129675a(12) =318153a(13) =778269a(14) =1899267a(15) =4625955a(16) =11249481a(17) =27321525a(18) =66285747a(19) =160679451a(20) =389217513a(21) =942260205a(22) =2280029379a(23) =5514901875a(24) =13334998953a(25) =32235231429a(26) =77906125107

External references