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 A137752 #8 Jun 22 2013 16:06:09 %S A137752 1,1,1,2,1,2,1,3,5,6,1,3,1,4,7,12,7,12,1,4,1,5,9,20,31,30,9,20,1,5,1, %T A137752 6,11,30,49,60,49,60,11,30,1,6,1,7,13,42,71,105,209,140,71,105,13,42, %U A137752 1,7,1,8,15,56,97,168,351,280,351,280,97,168 %N A137752 First numerator and then denominator (left to right) of Leibniz's harmonic-like triangle. %C A137752 In this triangle the right-hand edge consists of the reciprocals of the positive integers. A number that is not in this edge is obtained by adding the number diagonally above it to the number to its immediate right. Note that in Leibniz's harmonic triangle we subtract the two numbers to get a number which is not on the right-hand edge. %e A137752 1/1; %e A137752 1/2, 1/2; %e A137752 1/3, 5/6, 1/3; %e A137752 1/4, 7/12, 7/12, 1/4; %e A137752 1/5, 9/20, 31/30, 9/20, 1/5; %Y A137752 Cf. A003506; A007622; A046201; A046204; A046205; A046206; A046208; A046212. %Y A137752 Cf. A137753 %K A137752 frac,nonn,tabf,less %O A137752 1,4 %A A137752 _Mohammad K. Azarian_, Feb 10 2008