Dimension of 4-variable non-commutative harmonics (Hausdorff derivative). The dimension of the space of non-commutative polynomials in 4 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).
A122393
Dimension of 4-variable non-commutative harmonics (Hausdorff derivative). The dimension of the space of non-commutative polynomials in 4 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).
Terms
- a(0) =1a(1) =3a(2) =11a(3) =44a(4) =176a(5) =706a(6) =2824a(7) =11296a(8) =45183a(9) =180731a(10) =722925a(11) =2891700a(12) =11566800a(13) =46267200a(14) =185068800a(15) =740275200a(16) =2961100800a(17) =11844403200a(18) =47377612800a(19) =189510451200a(20) =758041804800
External references
- oeis: A122393