The On-Line Encyclopedia of Integer Sequences (OEIS)

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A217602

Let a(1) = 1. If n and a(n-1) have the same parity, a(n) = n + a(n-1), otherwise a(n) = abs(n - a(n-1)).
(history; published version)

#33 by Charles R Greathouse IV at Thu Sep 08 08:46:04 EDT 2022

PROG

(MAGMAMagma) m:=80; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(-x*(2*x^10+3*x^8-8*x^7-2*x^6-4*x^5+2*x^4-4*x^3 -4*x^2-1)/((x-1)^2*(x+ 1)*(x^2+1)^2*(x^4+1)))); // G. C. Greubel, Aug 31 2018

Discussion

Thu Sep 08

08:46

OEIS Server: https://oeis.org/edit/global/2944

#32 by Susanna Cuyler at Fri Aug 31 09:25:35 EDT 2018

STATUS

proposed

approved

#31 by G. C. Greubel at Fri Aug 31 02:01:30 EDT 2018

STATUS

editing

proposed

#30 by G. C. Greubel at Fri Aug 31 02:01:23 EDT 2018

LINKS

<a href="/index/Rec#order_11">Index entries for linear recurrences with constant coefficients</a>, signature (1,-1,1,0,0,0,0,1,-1,1,-1).

FORMULA

G.f.: -x*(2*x^10+3*x^8-8*x^7-2*x^6-4*x^5+2*x^4-4*x^3-4*x^2-1)/((x-1)^2*(x+1)*(x^2+1)^2*(x^4+1)). [_- _Colin Barker_, Oct 11 2012]

PROG

(PARI) x='x+O('x^80); Vec(-x*(2*x^10+3*x^8-8*x^7-2*x^6-4*x^5+2*x^4-4*x^3 -4*x^2-1)/((x-1)^2*(x+1)*(x^2+1)^2*(x^4+1))) \\ G. C. Greubel, Aug 31 2018

(MAGMA) m:=80; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(-x*(2*x^10+3*x^8-8*x^7-2*x^6-4*x^5+2*x^4-4*x^3 -4*x^2-1)/((x-1)^2*(x+ 1)*(x^2+1)^2*(x^4+1)))); // G. C. Greubel, Aug 31 2018

STATUS

approved

editing

#29 by Charles R Greathouse IV at Sat Jun 13 00:54:22 EDT 2015

LINKS

<a href="/index/Rec">Index to sequences with entries for linear recurrences with constant coefficients</a>, signature (1,-1,1,0,0,0,0,1,-1,1,-1).

Discussion

Sat Jun 13

00:54

OEIS Server: https://oeis.org/edit/global/2439

#28 by Charles R Greathouse IV at Fri Jun 12 15:28:08 EDT 2015

LINKS

<a href="/index/Rea#recLCCRec">Index to sequences with linear recurrences with constant coefficients</a>, signature (1,-1,1,0,0,0,0,1,-1,1,-1).

Discussion

Fri Jun 12

15:28

OEIS Server: https://oeis.org/edit/global/2436

#27 by Joerg Arndt at Fri Dec 28 04:36:10 EST 2012

STATUS

proposed

approved

#26 by Vincenzo Librandi at Fri Dec 28 02:55:56 EST 2012

STATUS

editing

proposed

#25 by Vincenzo Librandi at Fri Dec 28 02:55:47 EST 2012

LINKS

<a href="/index/Rea#recLCC">Index to sequences with linear recurrences with constant coefficients</a>, signature (1,-1,1,0,0,0,0,1,-1,1,-1).

#24 by Vincenzo Librandi at Fri Dec 28 02:54:58 EST 2012

LINKS

Vincenzo Librandi, <a href="/A217602/b217602.txt">Table of n, a(n) for n = 1..1000</a>

MATHEMATICA

CoefficientList[Series[-(2*x^10 + 3*x^8 - 8*x^7 - 2*x^6 - 4*x^5 + 2*x^4 - 4*x^3 - 4*x^2 - 1)/((x - 1)^2*(x + 1)*(x^2 + 1)^2*(x^4 + 1)), {x, 0, 100}], x] (* Vincenzo Librandi, Dec 28 2012 *)

STATUS

approved

editing