Number of nondecreasing strings of numbers x(i=1..7) in -n..n with sum x(i)^3 equal to 0.

Terms

a(0) =4a(1) =10a(2) =22a(3) =41a(4) =68a(5) =114a(6) =202a(7) =273a(8) =402a(9) =548a(10) =720a(11) =979a(12) =1248a(13) =1660a(14) =2072a(15) =2525a(16) =3068a(17) =3802a(18) =4498a(19) =5377a(20) =6632a(21) =7846a(22) =8998a(23) =10497a(24) =11970a(25) =13908a(26) =15870a(27) =18569a(28) =20582a(29) =23382