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 A113137 #14 Mar 21 2020 04:06:35 %S A113137 1,1,1,1,2,2,1,1,2,3,3,3,3,2,1,1,3,4,4,4,4,3,1,1,2,3,4,5,5,5,5,5,5,5, %T A113137 5,4,3,2,1,1,5,6,6,6,6,5,1,1,2,3,4,5,6,7,7,7,7,7,7,7,7,7,7,7,7,6,5,4, %U A113137 3,2,1,1,3,5,7,8,8,8,8,8,8,8,8,7,5,3,1,1,2,4,5,7,8,9,9,9,9,9,9,9,9,9,9,9,9 %N A113137 The rational numbers can be ordered by height and then by magnitude (see A002246, A097080); sequence gives denominators. %D A113137 M. N. Huxley, Area, Lattice Points and Exponential Sums, Oxford, 1996; p. 7. %H A113137 <a href="/index/Ra#rational">Index entries for sequences related to enumerating the rationals</a> %e A113137 The rationals with this ordering, with those of height k in row k (there are 4*A000010(k) rationals of height k, for k>1): %e A113137 -1 0 1 %e A113137 -2 -1/2 1/2 2 %e A113137 -3 -3/2 -2/3 -1/3 1/3 2/3 3/2 3 %e A113137 -4 -4/3 -3/4 -1/4 1/4 3/4 4/3 4 %e A113137 ... %Y A113137 Cf. A113136, A002246, A097080. %K A113137 nonn,easy,tabf %O A113137 1,5 %A A113137 _N. J. A. Sloane_, Nov 02 2008 %E A113137 More terms from _John W. Layman_, Nov 06 2008