Number of free generators of degree n of symmetric polynomials in 4 noncommuting variables.

A124292

Number of free generators of degree n of symmetric polynomials in 4 noncommuting variables.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =21a(5) =78a(6) =297a(7) =1143a(8) =4419a(9) =17118a(10) =66366a(11) =257391a(12) =998406a(13) =3873015a(14) =15024609a(15) =58285737a(16) =226111986a(17) =877174110a(18) =3402893997a(19) =13201132950a(20) =51212274057a(21) =198672129783a(22) =770725711035

External references