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 A137756 #7 Jun 22 2013 16:06:10 %S A137756 2,2,3,5,6,3,4,7,12,7,12,4,5,9,20,31,30,9,20,5,6,11,30,49,60,49,60,11, %T A137756 30,6,7,13,42,71,105,209,140,71,105,13,42,7,8,15,56,97,168,351,280, %U A137756 351,280,97,168,15,56,8,9,17,72,127,252,545,504,1471 %N A137756 Nontrivial elements in writing the numerator of an element first and then the denominator of that element (left to right) of Leibniz's harmonic-like triangle. That is, the nontrivial elements of A137752. %e A137756 1/1; --> %e A137756 1/2, 1/2; --> 2 2 %e A137756 1/3, 5/6, 1/3; --> 3 5 6 3 %e A137756 1/4, 7/12, 7/12, 1/4; --> ... %e A137756 1/5, 9/20, 31/30, 9/20, 1/5; %Y A137756 Cf. A003506; A007622; A046201; A046204; A046205; A046206; A046208; A046212; A137752; A137753; A137754; A137755. %K A137756 frac,nonn,tabf,less %O A137756 1,1 %A A137756 _Mohammad K. Azarian_, Feb 10 2008