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A289922 Coefficients of 1/([1+r] - [1+2r]x + [1+3r]x^2 - ...), where [ ] = floor and r = 19/21. 3
1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 1, 3, 3, 1, 0, 0, 0, 0, 0, 0, 1, 3, 3, 1, 0, 0, 0, 0, 0, 0, 1, 2, -1, -5, -4, -1, 0, 0, 0, 0, 1, 1, -6, -15, -14, -6, -1, 0, 0, 0, 1, 0, -10, -21, -18, -7, -1, 0, 0, 0, 1, -1, -13, -20, -3, 18, 18, 7, 1, 0, 1, -2, -15, -13, 29 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Ray Chandler, Table of n, a(n) for n = 0..10000

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

FORMULA

G.f.: 1/([1+r] - [1+2r]x + [1+3r]x^2 - ...), where [ ] = floor and r = 19/21.

G.f.: (1 + x)^2*(1 - x + x^2)*(1 - x + x^2 - x^3 + x^4 - x^5 + x^6)*(1 + x - x^3 - x^4 + x^6 - x^8 - x^9 + x^11 + x^12) / (1 - x + x^2 - x^3 + x^4 - x^5 + x^6 - x^7 + x^8 - x^9 - x^11 + x^12 - x^13 + x^14 - x^15 + x^16 - x^17 + x^18 - x^19 + x^20 + x^21). - Colin Barker, Jul 20 2017

MATHEMATICA

z = 2000; r = 19/21;

CoefficientList[Series[1/Sum[Floor[1 + (k + 1)*r] (-x)^k, {k, 0, z}], {x, 0, z}],

  x];

PROG

(PARI) Vec((1 + x)^2*(1 - x + x^2)*(1 - x + x^2 - x^3 + x^4 - x^5 + x^6)*(1 + x - x^3 - x^4 + x^6 - x^8 - x^9 + x^11 + x^12) / (1 - x + x^2 - x^3 + x^4 - x^5 + x^6 - x^7 + x^8 - x^9 - x^11 + x^12 - x^13 + x^14 - x^15 + x^16 - x^17 + x^18 - x^19 + x^20 + x^21) + O(x^100)) \\ Colin Barker, Jul 21 2017

CROSSREFS

Cf. A078140 (includes guide to related sequences), A289921, A289923.

Sequence in context: A196096 A249344 A067150 * A017887 A289923 A289921

Adjacent sequences:  A289919 A289920 A289921 * A289923 A289924 A289925

KEYWORD

easy,sign

AUTHOR

Clark Kimberling, Jul 18 2017

STATUS

approved

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Last modified April 24 00:02 EDT 2019. Contains 322404 sequences. (Running on oeis4.)