Number of ordered solutions to x+y+z = u+v+w, 0 <= x, y, z, u, v, w < n.

Terms

a(0) =1a(1) =20a(2) =141a(3) =580a(4) =1751a(5) =4332a(6) =9331a(7) =18152a(8) =32661a(9) =55252a(10) =88913a(11) =137292a(12) =204763a(13) =296492a(14) =418503a(15) =577744a(16) =782153a(17) =1040724a(18) =1363573a(19) =1762004a(20) =2248575a(21) =2837164a(22) =3543035a(23) =4382904a(24) =5375005a(25) =6539156a(26) =7896825a(27) =9471196a(28) =11287235a(29) =13371756