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 A182974 #10 Mar 30 2012 18:39:49 %S A182974 1,2,7,158,1617,6211,8058,16765,69093,465988,5297983,6546724,18588348, %T A182974 38244610,204136352,430712111,2760559191,100878516991,440393924631 %N A182974 Numbers n for which A020652(n)/A038567(n) = A182972(n)/A182973(n). %C A182974 Numerators of the matching fractions are given in A182975. %C A182974 Denominators of the matching fractions are given in A182976. %C A182974 The initial (zeroth) term of A038567 is ignored. %D A182974 S. Cook, Problem 511: An Enumeration Problem, Journal of Recreational Mathematics, Vol. 9:2 (1976-77), 137. Solution by the Problem Editor, JRM, Vol. 10:2 (1977-78), 122-123. %H A182974 Paul Yiu, <a href="http://math.fau.edu/Yiu/RecreationalMathematics2003.pdf">Recreational Mathematics</a>, 24.3.1 Appendix: Two enumerations of the rational numbers in (0,1), page 633. %e A182974 a(1)=1, a(2)=2 and a(3)=7 because the 1st, 2nd and 7th fractions match in the following two sequences: %e A182974 1/2, 1/3, 2/3, 1/4, 3/4, 1/5, 2/5, 3/5 ... (A020652/A038567) %e A182974 1/2, 1/3, 1/4, 2/3, 1/5, 1/6, 2/5, 3/4 ... (A182972/A182973) %Y A182974 Cf. A020652, A038567, A182972, A182973, A182975, A182976. %K A182974 nonn,more %O A182974 1,2 %A A182974 _William Rex Marshall_, Dec 16 2010