A169722 a(n) = (3*2^(n-1)-1)*(18*2^(n-1)-7).

1, 22, 145, 715, 3151, 13207, 54055, 218695, 879751, 3528967, 14135815, 56583175, 226412551, 905809927, 3623559175, 14494875655, 57980780551, 231925678087, 927707824135, 3710841520135, 14843386527751, 59373587005447, 237494429810695, 949977882820615

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Alice V. Kleeva, Grid for this sequence

Alice V. Kleeva, Illustration of initial terms

Robert Munafo, Sequence A169720, and two others by Alice V. Kleeva

Robert Munafo, Sequence A169720, and two others by Alice V. Kleeva [Cached copy, in pdf format, included with permission]

Index entries for linear recurrences with constant coefficients, signature (7,-14,8).

Formula

G.f.: (1+15*x+5*x^2)/(1-7*x+14*x^2-8*x^3). - Bruno Berselli, Dec 04 2012

a(n) = 7*a(n-1)-14*a(n-2)+8*a(n-3). - Vincenzo Librandi, Dec 04 2012

Mathematica

LinearRecurrence[{7, -14, 8}, {1, 22, 145}, 30] (* Vincenzo Librandi, Dec 04 2012 *)

Prog

(Magma) I:=[1, 22, 145]; [n le 3 select I[n] else 7*Self(n-1)-14*Self(n-2)+8*Self(n-3): n in [1..30]]; // Vincenzo Librandi, Dec 04 2012
(Maxima) makelist(coeff(taylor((1+15*x+5*x^2)/(1-7*x+14*x^2-8*x^3), x, 0, n), x, n), n, 0, 23); /* Bruno Berselli, Dec 04 2012 */

Crossrefs

Cf. A169720-A169727, A033484.

Sequence in context: A125332 A126490 A200776 * A262139 A159505 A223836

Adjacent sequences: A169719 A169720 A169721 * A169723 A169724 A169725

Keyword

nonn,easy

Author

Alice V. Kleeva (alice27353(AT)gmail.com), Jan 19 2010

Status

approved