A079673 - OEIS

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A079673

Consider pairs (r,s) such that the polynomial (x^r+1) divides (x^s+1) and 1 <= r < s. This sequence gives the r values; A079581 gives the s values.

1, 1, 2, 1, 1, 3, 2, 1, 4, 1, 2, 1, 3, 5, 1, 2, 6, 1, 4, 1, 3, 7, 2, 1, 8, 1, 5, 2, 1, 3, 9, 4, 1, 2, 6, 10, 1, 1, 3, 11, 2, 1, 5, 7, 4, 12, 1, 2, 1, 3, 13, 8, 1, 2, 6, 14, 1, 4, 1, 3, 5, 9, 15, 2, 1, 16, 1, 7, 2, 10, 1, 3, 17, 4, 1, 2, 6, 18, 1, 5, 11, 8, 1, 3, 19, 2, 1, 4, 12, 20, 1, 2, 1, 3, 7, 9, 21, 1

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OFFSET

1,3

COMMENTS

(x^r+1) divides (x^s+1) iff s/r is an odd integer.

LINKS

Table of n, a(n) for n=1..98.

EXAMPLE

a(5)=1 and a(6)=3 because A079581(5)=A079581(6)=9 and (x^1+1) and (x^3+1) divide (x^9+1).

CROSSREFS

Cf. A079581, A079665, A079672.

Sequence in context: A184751 A355534 A296150 * A124829 A093394 A094363