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A048467 a(n) = T(6,n), array T given by A047858. 1
1, 8, 23, 55, 123, 267, 571, 1211, 2555, 5371, 11259, 23547, 49147, 102395, 212987, 442363, 917499, 1900539, 3932155, 8126459, 16777211, 34603003, 71303163, 146800635, 301989883, 620756987, 1275068411, 2617245691 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..3000

Index entries for linear recurrences with constant coefficients, signature (5, -8, 4).

FORMULA

G.f.: (-9*x^2+3*x+1)/((1-x)*(1-2*x)^2).

a(n) = 5*a(n-1) - 8*a(n-2) + 4*a(n-3). - Harvey P. Dale, Jul 07 2011

a(n) = 2^(n-1)*(n+12)-5. - Vincenzo Librandi, Sep 28 2011

MATHEMATICA

LinearRecurrence[{5, -8, 4}, {1, 8, 23}, 30] (* or *) CoefficientList[ Series[ (-9x^2+3x+1)/((1-x)(1-2x)^2), {x, 0, 30}], x] (* Harvey P. Dale, Jul 07 2011 *)

PROG

(MAGMA) [2^(n-1)*(n+12)-5: n in [0..30]]; // Vincenzo Librandi, Sep 28 2011

(PARI) Vec((-9*x^2+3*x+1)/((1-x)*(1-2*x)^2) + O(x^40)) \\ Andrew Howroyd, Feb 15 2018

CROSSREFS

n-th difference of a(n), a(n-1), ..., a(0) is (7, 8, 9, ...).

Sequence in context: A218711 A270694 A027054 * A002765 A048770 A055273

Adjacent sequences:  A048464 A048465 A048466 * A048468 A048469 A048470

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified October 23 07:20 EDT 2018. Contains 316520 sequences. (Running on oeis4.)