27246

Appears in sequences

• Number of regions in regular n-gon which are quadrilaterals (4-gons) when all its diagonals are drawn.at n=34A067151
• Number of separable involutions.at n=11A121704
• Number of n X n 0..2 arrays with rows and columns unimodal and antidiagonals nondecreasing.at n=3A224051
• Number of n X 4 0..2 arrays with rows and columns unimodal and antidiagonals nondecreasing.at n=3A224053
• T(n,k)=Number of nXk 0..2 arrays with rows and columns unimodal and antidiagonals nondecreasing.at n=24A224057
• Expansion of e.g.f. -LambertW(-x) * Product_{k>=1} 1/(1-x^k).at n=6A317103
• a(n) = Sum_{k=1..n} k^3 * n^(n-k).at n=6A368525