374220

Appears in sequences

• Number of double tangents of order n.at n=30A060784
• a(n) = 27*(n-1)*(n-2)*(n-3)*(3*n-8)/2.at n=10A064197
• a(n) = n^2*(n+1)*(2*n+1)/3.at n=26A098077
• Triangle read by rows: T(n,k) is the sum of the weights of all vertices labeled k at depth n in the Catalan tree (1 <= k <= n+1, n >= 0).at n=30A102625
• Triangle T, read by rows, such that the matrix square, T^2, forms a simple 2-diagonal triangle where [T^2](n,n) = 1 and [T^2](n+1,n) = 2*(n+1) for n>=0.at n=47A113278
• Production array of A122848, read by row.at n=57A154557
• Number of inversions in all fixed-point-free involutions of {1,2,...,2n}.at n=6A161124
• A Galton triangle: T(n,k) = (2k-1)*(T(n-1,k) + T(n-1,k-1)): a type B analog of the ordered Bell numbers A019538.at n=26A186695
• Augmentation of the triangle A004736. See Comments.at n=33A193561