This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A079673 #7 Oct 19 2017 03:14:11 %S A079673 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 A079673 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 A079673 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 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. %C A079673 (x^r+1) divides (x^s+1) iff s/r is an odd integer. %e A079673 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 A079673 Cf. A079581, A079665, A079672. %K A079673 nonn %O A079673 1,3 %A A079673 Jose R. Brox (tautocrona(AT)terra.es), Jan 25 2003 %E A079673 Edited by _Don Reble_, Jun 12 2003