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 A113136 #15 Mar 21 2020 04:06:26 %S A113136 -1,0,1,-2,-1,1,2,-3,-3,-2,-1,1,2,3,3,-4,-4,-3,-1,1,3,4,4,-5,-5,-5,-5, %T A113136 -4,-3,-2,-1,1,2,3,4,5,5,5,5,-6,-6,-5,-1,1,5,6,6,-7,-7,-7,-7,-7,-7,-6, %U A113136 -5,-4,-3,-2,-1,1,2,3,4,5,6,7,7,7,7,7,7,-8,-8,-8,-8,-7,-5,-3,-1,1,3,5,7 %N A113136 The rational numbers can be ordered by height and then by magnitude (see A002246, A097080); sequence gives numerators. %D A113136 M. N. Huxley, Area, Lattice Points and Exponential Sums, Oxford, 1996; p. 7. %H A113136 <a href="/index/Ra#rational">Index entries for sequences related to enumerating the rationals</a> %e A113136 The rationals with this ordering, with those of height k in row k (there are three of height 1, and 4*A000010(k) rationals of height k, for k>1): %e A113136 -1 0 1 %e A113136 -2 -1/2 1/2 2 %e A113136 -3 -3/2 -2/3 -1/3 1/3 2/3 3/2 3 %e A113136 -4 -4/3 -3/4 -1/4 1/4 3/4 4/3 4 %e A113136 ... %Y A113136 Cf. A113137, A002246, A097080. %K A113136 sign,easy,tabf %O A113136 1,4 %A A113136 _N. J. A. Sloane_, Nov 02 2008 %E A113136 More terms from _John W. Layman_, Nov 06 2008