286978140

Appears in sequences

• Expansion of 1/(3*x^2 - 3*x + 1)^2.at n=28A115052
• a(n) = 3*a(n-1), with a(1) = 20.at n=15A116530
• Sum of the lengths of the drops in all ternary words of length n on {0,1,2}. The drops of a ternary word on {0,1,2} are the subwords 10,20 and 21, their lengths being the differences 1, 2 and 1, respectively.at n=15A120908
• (n-1)-st elementary symmetric function of the first n terms of A010684.at n=29A203230
• (n-1)-st elementary symmetric function of the first n terms of the periodic sequence (3,1,3,1,3,1,3,1,...).at n=29A203231
• Number of n X 2 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three exactly once.at n=7A269270