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 A049448 #5 Mar 31 2012 20:38:26 %S A049448 1,2,3,4,5,5,7,8,7,6,9,11,10,11,13,12,9,7,11,14,13,15,18,17,13,14,19, %T A049448 21,18,17,19,16,11,8,13,17,16,19,23,22,17,19,26,29,25,24,27,23,16,17, %U A049448 25,30,27,29,34,31,23,22,29,31,26,23,25,20,13,9,15,20,19,23 %N A049448 Sum of numerator and denominator of fractions in Farey tree A007305/A007306. %D A049448 J. C. Lagarias, Number Theory and Dynamical Systems, pp. 35-72 of S. A. Burr, ed., The Unreasonable Effectiveness of Number Theory, Proc. Sympos. Appl. Math., 46 (1992). Amer. Math. Soc. %F A049448 A007305+A007306. %Y A049448 Subset of A007306. Cf. A049465-A049468. %K A049448 nonn,easy,nice,tabf %O A049448 0,2 %A A049448 _N. J. A. Sloane_, _Gregory V. Richardson_