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 A137767 #8 Jun 22 2013 16:06:10 %S A137767 2,3,7,12,4,9,20,5,49,60,11,30,6,71,105,13,42,7,351,280,97,168,15,56, %T A137767 8,545,504,127,252,17,72,9,2561,1260,799,840,161,360,19,90,10,4159, %U A137767 2310,1121,1320,199,495,21,110,11 %N A137767 Nontrivial numbers of the elements to the right of the central elements in writing first the numerator and then the denominator (left to right) of Leibniz's harmonic-like triangle. %e A137767 1/1; --> %e A137767 1/2, 1/2; --> 2 %e A137767 1/3, 5/6, 1/3; --> 3 %e A137767 1/4, 7/12, 7/12, 1/4; --> 7 12 %e A137767 1/5, 9/20, 31/30, 9/20, 1/5; --> ... %Y A137767 Cf. A137752. %Y A137767 Cf. A046201, A046204, A046205, A046206, A046208, A046212, A137752, A137753, A137754, A137755, A137756, A137757, A137758, A137759, A137760, A137761, A137762, A137763, A137764, A137765, A137766. %K A137767 nonn,tabf,frac,less %O A137767 1,1 %A A137767 _Mohammad K. Azarian_, Feb 13 2008