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A121203 2n+7^n-5^n. 1
0, 4, 28, 224, 1784, 13692, 102036, 745432, 5374192, 38400500, 272709644, 1928498640, 13597146600, 95668307308, 672119557252, 4717043931848, 33080342679008, 231867574534116, 1624598900644860, 11379821699045056 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (14,-60,82,-35).

FORMULA

G.f.: 4*x*(1-7*x+18*x^2)/((1-x)^2*(1-5*x)*(1-7*x)). - Vincenzo Librandi, Feb 25 2013

a(n) = 14*a(n-1)-60*a(n-2)+82*a(n-3)-35*a(n-4). - Vincenzo Librandi, Feb 26 2013

MATHEMATICA

CoefficientList[Series[4 x (1 - 7 x + 18 x^2)/((1-x)^2 (1-5 x)(1-7 x)), {x, 0, 30}], x] (* Vincenzo Librandi, Feb 25 2013 *)

PROG

(MAGMA) [2*n+7^n-5^n: n in [0..30]] /* or */ I:=[0, 4, 28, 224]; [n le 4 select I[n] else 14*Self(n-1)-60*Self(n-2)+82*Self(n-3)-35*Self(n-4): n in [1..20]]; // Vincenzo Librandi, Feb 26 2013

CROSSREFS

Cf. A074616.

Sequence in context: A243116 A026033 A005810 * A192620 A180708 A191094

Adjacent sequences:  A121200 A121201 A121202 * A121204 A121205 A121206

KEYWORD

nonn,easy

AUTHOR

Mohammad K. Azarian, Aug 19 2006

EXTENSIONS

Edited by Ray Chandler, Sep 06 2006

STATUS

approved

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Last modified August 26 05:23 EDT 2019. Contains 326328 sequences. (Running on oeis4.)