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A289912 Coefficients of 1/(Sum_{k>=0} round((k+1)*r)(-x)^k), where r = sqrt(2). 2
1, 3, 5, 9, 18, 35, 66, 124, 234, 441, 829, 1557, 2925, 5496, 10325, 19394, 36429, 68428, 128532, 241425, 453475, 851775, 1599910, 3005145, 5644626, 10602419, 19914742, 37406262, 70260933, 131972522, 247886635, 465610427, 874565375, 1642713630, 3085541851 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Conjecture: the sequence is strictly increasing.

LINKS

Table of n, a(n) for n=0..34.

FORMULA

G.f.:  1/(Sum_{k>=0} round((k+1)*r)(-x)^k), where r = sqrt(2).

MATHEMATICA

z = 100; r = Sqrt[2];

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

  x];  (* A289912 *)

v = N[u[[z]]/u[[z - 1]], 200]

d = RealDigits[v, 10][[1]] (* A289913 *)

CROSSREFS

Cf. A078140 (includes guide to related sequences), A289913.

Sequence in context: A281852 A120941 A108227 * A289914 A251704 A288230

Adjacent sequences:  A289909 A289910 A289911 * A289913 A289914 A289915

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling, Jul 18 2017

STATUS

approved

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Last modified July 27 21:21 EDT 2021. Contains 346316 sequences. (Running on oeis4.)