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

Terms

a(0) =4a(1) =16a(2) =43a(3) =92a(4) =167a(5) =275a(6) =422a(7) =615a(8) =858a(9) =1158a(10) =1521a(11) =1954a(12) =2461a(13) =3049a(14) =3724a(15) =4493a(16) =5360a(17) =6332a(18) =7415a(19) =8616a(20) =9939a(21) =11391a(22) =12978a(23) =14707a(24) =16582a(25) =18610a(26) =20797a(27) =23150a(28) =25673a(29) =28373