3844787

Appears in sequences

• Whitney number of level n of the lattice of the ideals of the fence of order 2n.at n=18A051286
• Largest Whitney number of Fibonacci lattices J(Z_n).at n=36A077419
• Binomial sums a(n) = Sum_{k=0..n} (binomial(2n-k,k))^2.at n=9A188648