236160

Appears in sequences

• Expansion of e.g.f. 1/(1-2*x-2*x^2).at n=6A052611
• Triangle, T(n, k) = k^6 - n^6 - 5*(n*k)^2*(n^2 - k^2) + 4*n*k*((n*k)^4 - 1), read by rows.at n=9A123964
• a(n) = 729*n^2 - 2*n.at n=17A158394
• Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^10 = I.at n=11A165756
• (n-1)-st elementary symmetric function of {2, 2, 3, 3, 4, 4, 5, 5, ..., floor((n+3)/2)}.at n=8A203153
• Number of n X 6 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 0 1 1 vertically.at n=10A208067
• Triangle T(n,k), n>=3, 3<=k<=n, read by rows. Number of ways to make n selections without replacement from a circular array of n unlabeled cells (ignoring rotations and reflection), such that the first selection of a cell adjacent to previously selected cells occurs on the k-th selection.at n=38A249796
• Multi-table menage seating arrangements: T(n,k) for n,k >= 1 equals the number of ways to seat n*k married couples at n round tables with 2*k seats each, such that (i) the gender of persons alternates around each table; and (ii) spouses do not sit next to each other.at n=8A277257