a(n) = n^3 + (n+1)^3 + (n+2)^3.

Terms

a(0) =9a(1) =36a(2) =99a(3) =216a(4) =405a(5) =684a(6) =1071a(7) =1584a(8) =2241a(9) =3060a(10) =4059a(11) =5256a(12) =6669a(13) =8316a(14) =10215a(15) =12384a(16) =14841a(17) =17604a(18) =20691a(19) =24120a(20) =27909a(21) =32076a(22) =36639a(23) =41616a(24) =47025a(25) =52884a(26) =59211a(27) =66024a(28) =73341a(29) =81180