Number of strings of numbers x(i=1..n) in 0..2 with sum i^3*x(i)^2 equal to n^3*4.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =2a(6) =2a(7) =5a(8) =9a(9) =12a(10) =28a(11) =52a(12) =101a(13) =210a(14) =478a(15) =1013a(16) =1899a(17) =4175a(18) =8441a(19) =17794a(20) =36273a(21) =74831a(22) =153258a(23) =314354a(24) =630669a(25) =1275787a(26) =2563582a(27) =5137717a(28) =10176417a(29) =20206831