Number of solutions (x,y,z,u,v,w) to x+y+z = u+v+w, 0<=x,y,z,u,v,w<=n-1, x>=y>=z, u>=v>=w.

Terms

a(0) =1a(1) =4a(2) =16a(3) =48a(4) =119a(5) =256a(6) =500a(7) =900a(8) =1525a(9) =2456a(10) =3796a(11) =5664a(12) =8207a(13) =11588a(14) =16004a(15) =21672a(16) =28845a(17) =37800a(18) =48856a(19) =62356a(20) =78691a(21) =98280a(22) =121592a(23) =149128a(24) =181445a(25) =219132a(26) =262840a(27) =313256a(28) =371131a(29) =437256