a(n) = (10*n + 5)^3.

Terms

a(0) =125a(1) =3375a(2) =15625a(3) =42875a(4) =91125a(5) =166375a(6) =274625a(7) =421875a(8) =614125a(9) =857375a(10) =1157625a(11) =1520875a(12) =1953125a(13) =2460375a(14) =3048625a(15) =3723875a(16) =4492125a(17) =5359375a(18) =6331625a(19) =7414875a(20) =8615125a(21) =9938375a(22) =11390625a(23) =12977875a(24) =14706125a(25) =16581375a(26) =18609625a(27) =20796875a(28) =23149125a(29) =25672375