a(n) = (12*n+1)^3.

Terms

a(0) =1a(1) =2197a(2) =15625a(3) =50653a(4) =117649a(5) =226981a(6) =389017a(7) =614125a(8) =912673a(9) =1295029a(10) =1771561a(11) =2352637a(12) =3048625a(13) =3869893a(14) =4826809a(15) =5929741a(16) =7189057a(17) =8615125a(18) =10218313a(19) =12008989a(20) =13997521a(21) =16194277a(22) =18609625a(23) =21253933a(24) =24137569a(25) =27270901a(26) =30664297a(27) =34328125a(28) =38272753