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A246885 Those n for which the coefficients of x^n in the reciprocal of 1+x+x^8+...+x^(i^3)+... are odd. 2
0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 15, 16, 19, 20, 23, 29, 32, 34, 35, 37, 45, 47, 48, 49, 53, 54, 57, 58, 67, 69, 71, 73, 75, 85, 86, 99, 101, 107, 108, 109, 110, 115, 121, 123, 124, 127, 128, 129, 131, 132, 135, 137, 141, 143, 155, 157, 160, 161, 162, 163, 169, 177, 183, 189, 193, 195, 197, 199, 203 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Numbers n such that the number of compositions of n into cubes (A023358) is odd. - Joerg Arndt, Sep 08 2014

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..10000

J. N. Cooper, D. Eichhorn and K. O'Bryant, Reciprocals of binary power series, arXiv:math/0506496 [math.NT], 2005.

EXAMPLE

The reciprocal of 1+x+x^8+x^27+... begins 1 -x +x^2 -x^3 +x^4 -x^5 +x^6 -x^7 +x^9 -2*x^10 +...  So the first few values of a(n) are 0,1,2,3,4,5,6,7,9... .

MAPLE

b:= proc(n) option remember; irem(`if`(n=0, 1,

      `if`(n<0, 0, add(b(n-i^3), i=1..iroot(n, 3)))), 2)

    end:

a:= proc(n) option remember; local k; for k from 1+

      `if`(n=1, -1, a(n-1)) while b(k)=0 do od; k

    end:

seq(a(n), n=1..80);  # Alois P. Heinz, Sep 08 2014

MATHEMATICA

iend=10;

seq=Flatten[Position[Delete[Mod[CoefficientList[Series[1/Sum[x^(i^3), {i, 0, iend}], {x, 0, iend^3}], x], 2], 1], 1]];

Print[seq];

CROSSREFS

Cf. A023358.

Sequence in context: A210845 A057202 A277417 * A033059 A031876 A292621

Adjacent sequences:  A246882 A246883 A246884 * A246886 A246887 A246888

KEYWORD

nonn

AUTHOR

David S. Newman, Sep 06 2014

STATUS

approved

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Last modified June 24 23:16 EDT 2021. Contains 345445 sequences. (Running on oeis4.)