A139740 a(n) = 11^n - 2^n.

0, 9, 117, 1323, 14625, 161019, 1771497, 19487043, 214358625, 2357947179, 25937423577, 285311668563, 3138428372625, 34522712135739, 379749833566857, 4177248169382883, 45949729863506625, 505447028499162699, 5559917313491969337, 61159090448414022003, 672749994932558960625

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..300

Index entries for linear recurrences with constant coefficients, signature (13,-22).

Formula

a(n) = 13*a(n-1) - 22*a(n-2). - Vincenzo Librandi, Jun 02 2011

a(n) = A001020(n) - A000079(n). - Michel Marcus, Feb 28 2022

a(n) = 9*A016135(n-1), n > 0. - Bernard Schott, Mar 09 2022

E.g.f.: exp(2*x)*(exp(9*x) - 1). - Stefano Spezia, Mar 09 2025

G.f.: 9*x/((1-2*x)*(1-11*x)). - Elmo R. Oliveira, Mar 15 2025

Mathematica

Table[11^n - 2^n, {n, 0, 20}] (* or *)
LinearRecurrence[{13, -22}, {0, 9}, 21] (* Paolo Xausa, Mar 16 2025 *)

Prog

(SageMath) [11^n - 2^n for n in range(0, 20)] # Zerinvary Lajos, Jun 05 2009
(Magma) [11^n-2^n: n in [0..30]]; // Vincenzo Librandi, Jun 02 2011
(PARI) a(n)=11^n-2^n \\ Charles R Greathouse IV, Mar 26 2012
(Python) [11**n-2**n for n in range(20)] # Gennady Eremin, Mar 05 2022

Crossrefs

Cf. A000079, A001020, A016135.

Sequence in context: A253655 A092913 A022607 * A221442 A196663 A292843

Adjacent sequences: A139737 A139738 A139739 * A139741 A139742 A139743

Keyword

nonn,easy

Author

N. J. A. Sloane, May 20 2008

Status

approved