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%I #7 Oct 19 2017 03:14:11
%S 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,
%T 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,
%U 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
%N 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.
%C (x^r+1) divides (x^s+1) iff s/r is an odd integer.
%e 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).
%Y Cf. A079581, A079665, A079672.
%K nonn
%O 1,3
%A Jose R. Brox (tautocrona(AT)terra.es), Jan 25 2003
%E Edited by _Don Reble_, Jun 12 2003
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