A139745 a(n) = 11^n - 7^n.

0, 4, 72, 988, 12240, 144244, 1653912, 18663628, 208594080, 2317594084, 25654949352, 283334343868, 3124587089520, 34425823133524, 379071610510392, 4172500607905708, 45916496933002560, 505214397985306564, 5558288899894321032, 61147691553229173148

Offset

0,2

Links

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

Index entries for linear recurrences with constant coefficients, signature (18,-77).

Formula

a(n) = 18*a(n-1) - 77*a(n-2). - Vincenzo Librandi, Jun 02 2011

From Stefano Spezia, Mar 09 2025: (Start)

G.f.: 4*x/((1 - 11*x)*(1 - 7*x)).

E.g.f.: exp(7*x)*(exp(4*x) - 1). (End)

Mathematica

Table[11^n-7^n, {n, 0, 30}] (* or *) LinearRecurrence[{18, -77}, {0, 4}, 30] (* Harvey P. Dale, Jun 17 2014 *)

Prog

(Magma) [11^n-7^n: n in [0..30]]; // Vincenzo Librandi, Jun 02 2011

Crossrefs

Cf. A000420, A001020.

Sequence in context: A192830 A119580 A209539 * A066992 A165212 A263219

Adjacent sequences: A139742 A139743 A139744 * A139746 A139747 A139748

Keyword

nonn,easy,changed

Author

N. J. A. Sloane, May 20 2008

Status

approved