32206

Appears in sequences

• Expansion of 1/((1+x)*(1-x)^10).at n=9A001781
• Number of nodes of even outdegree (including leaves) in all ordered trees with n edges.at n=9A026641
• a(n) = A026637(n, floor(n/2)).at n=17A026643
• Number of symmetric Dyck paths of semilength n and having no hills (i.e., no peaks at level 1).at n=18A109078
• A tree-node counting triangle.at n=45A109244
• Triangle T(n,k) read by rows, matrix product of A046899(row-reversed) * A130595.at n=45A158815
• Triangle T, read by rows : T(n,k) = A007318(n,k)*A026641(n-k).at n=45A171650
• Number left factors of Dyck paths of length n and having no hills; a hill is a (1,1)-step starting at level 0 and followed by a (1,-1)-step.at n=18A191526
• Number of (n+2)X4 0..3 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..3 introduced in row major order.at n=7A204636
• T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..3 introduced in row major order.at n=37A204642
• Centered pentagonal numbers which are squarefree semiprimes.at n=40A381043
• Centered pentagonal numbers which are semiprimes.at n=41A382132