A117197 a(n) = (n^3 - 1)^3.

0, 343, 17576, 250047, 1906624, 9938375, 40001688, 133432831, 385828352, 997002999, 2352637000, 5150827583, 10590025536, 20638466407, 38409197624, 68669157375, 118515478528, 198257271191, 322546580712, 511808023999

Offset: 1

Author

Luc Stevens (lms022(AT)yahoo.com), Apr 21 2006

Keywords

• nonn
• easy

Comments

Cubes a(1-1),a(8-1),a(27-1),a(64-1),...

Crossrefs

Cf. A000578 (n^3), A068601 (n^3-1).

Programs

Mathematica

(Range[20]^3-1)^3 (* Harvey P. Dale, Mar 25 2013 *)

Formula

a(n) = n^9 - 3n^6 + 3n^3 - 1.

G.f.: (x^9-2*x^8+694*x^7+14902*x^6+87160*x^5+155914*x^4+89722*x^3+14146*x^2+ 343*x)/(x-1)^10. - Harvey P. Dale, Mar 25 2013 [corrected by Georg Fischer, May 15 2019]

a(n) = A000578(A068601(n)). - Michel Marcus, May 15 2019

Extensions

Edited and corrected by Franklin T. Adams-Watters, Apr 26 2006