Number of strings of numbers x(i=1..n) in 0..3 with sum i^2*x(i)^3 equal to n^2*27.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =2a(6) =6a(7) =30a(8) =69a(9) =230a(10) =662a(11) =2244a(12) =6197a(13) =20782a(14) =57963a(15) =185236a(16) =534294a(17) =1636436a(18) =4788888a(19) =14148505a(20) =41505698a(21) =119551191a(22) =347802192a(23) =984873101a(24) =2823972122a(25) =7899999963a(26) =22281193586a(27) =61710573450a(28) =171287868395a(29) =469925476292