

A288231


Coefficients of 1/(Sum_{k>=0} [(k+1)*r](x)^k), where r = 4^(1/3) and [ ] = floor.


2



1, 3, 5, 9, 18, 36, 71, 138, 268, 522, 1017, 1981, 3859, 7517, 14642, 28521, 55557, 108223, 210814, 410654, 799931, 1558224, 3035341, 5912689, 11517614, 22435718, 43703622, 85132404, 165833537, 323035186, 629255898, 1225758065, 2387713549, 4651142959
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OFFSET

0,2


COMMENTS

Conjecture: the sequence is strictly increasing.


LINKS

Table of n, a(n) for n=0..33.


FORMULA

G.f.: 1/(Sum_{k>=0} [(k+1)*r)](x)^k), where r = 4^(1/3) and [ ] = floor.


MATHEMATICA

r = Sqrt[5/2];
u = 1000; (* # initial terms from given series *)
v = 100; (* # coefficients in reciprocal series *)
CoefficientList[Series[1/Sum[Floor[r*(k + 1)] (x)^k, {k, 0, u}], {x, 0, v}], x]


CROSSREFS

Cf. A078140 (includes guide to related sequences).
Sequence in context: A251704 A288230 A289262 * A279592 A288229 A293332
Adjacent sequences: A288228 A288229 A288230 * A288232 A288233 A288234


KEYWORD

nonn,easy


AUTHOR

Clark Kimberling, Jul 10 2017


STATUS

approved



