Number of strings of numbers x(i=1..n) in 0..3 with sum i*x(i)^4 equal to n*81.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =6a(5) =10a(6) =17a(7) =45a(8) =153a(9) =561a(10) =1670a(11) =4780a(12) =14974a(13) =45555a(14) =140211a(15) =419924a(16) =1245122a(17) =3669858a(18) =10724147a(19) =31185503a(20) =89840674a(21) =256746801a(22) =728672328a(23) =2051488536a(24) =5732076608a(25) =15895090361a(26) =43752447121a(27) =119570863227a(28) =324496444134