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A204631 Expansion of 1/(1 - x - x^2 + x^5 - x^7). 32
1, 1, 2, 3, 5, 7, 11, 17, 26, 40, 62, 96, 148, 229, 354, 547, 845, 1306, 2018, 3118, 4818, 7445, 11504, 17776, 27468, 42444, 65585, 101343, 156597, 241976, 373905, 577764, 892770, 1379522, 2131659, 3293873, 5089744, 7864752, 12152738, 18778601, 29016988 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Limiting ratio is 1.5452156..., the real root of x^7 - x^6 - x^5 + x^2 - 1.

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (1,1,0,0,-1,0,1).

FORMULA

a(n) = a(n-1) + a(n-2) - a(n-5) + a(n-7). - Franck Maminirina Ramaharo, Nov 02 2018

MATHEMATICA

CoefficientList[Series[1/(1 - x - x^2 + x^5 - x^7), {x, 0, 50}], x]

LinearRecurrence[{1, 1, 0, 0, -1, 0, 1}, {1, 1, 2, 3, 5, 7, 11}, 50] (* Harvey P. Dale, Aug 28 2013 *)

PROG

(PARI) Vec(1/(1-x-x^2+x^5-x^7) + O(x^90)) \\ G. C. Greubel, Nov 16 2016

(MAGMA) m:=50; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1-x-x^2+x^5-x^7))); // G. C. Greubel, Nov 03 2018

CROSSREFS

Cf. A029826, A117791, A143419, A143438, A143472, A143619, A143644, A147663, A173908, A173911, A173924, A173925, A174522, A175740, A175772, A175773, A175782, A181600, A225391, A225393, A225394, A225482, A225499.

Sequence in context: A018058 A002379 A072465 * A323361 A052284 A133670

Adjacent sequences:  A204628 A204629 A204630 * A204632 A204633 A204634

KEYWORD

nonn,easy

AUTHOR

Roger L. Bagula, Jan 17 2012

STATUS

approved

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Last modified November 19 06:03 EST 2019. Contains 329310 sequences. (Running on oeis4.)