Dimensions of certain Lie algebra (see reference for precise definition).

Terms

a(0) =1a(1) =21a(2) =210a(3) =1386a(4) =6930a(5) =28314a(6) =99099a(7) =306735a(8) =858858a(9) =2212210a(10) =5309304a(11) =11992344a(12) =25697880a(13) =52581816a(14) =103285710a(15) =195635286a(16) =358664691a(17) =638489775a(18) =1106715610a(19) =1872263250a(20) =3097744650a(21) =5021809650a(22) =7989242625a(23) =12491007165a(24) =19216934100a(25) =29124331236a(26) =43526473056