909792

Appears in sequences

• a(n) = Sum_{k=0..2n} (k+1) * A026552(n, k).at n=12A027276
• Dimension of 3-variable non-commutative harmonics (Hausdorff derivative). The dimension of the space of non-commutative polynomials in 3 variables which are killed by all symmetric differential operators (where for a monomial w, d_{xi} ( w ) = sum over all subwords of w deleting xi once).at n=13A122392