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 A137759 #7 Jun 22 2013 16:06:10 %S A137759 1,1,1,1,1,3,5,1,3,1,7,7,1,1,5,9,31,9,1,5,1,11,49,49,11,1,1,7,13,71, %T A137759 105,209,71,105,13,1,7,1,15,97,351,351,97,15,1,1,9,17,127,545,1471, %U A137759 545,127,17,1,9,1,19,161,799,2561,2561,799,161,19,1 %N A137759 Odd numbers in writing first numerator and then denominator (left to right) of Leibniz's harmonic-like triangle. %e A137759 1/1; --> 1 1 %e A137759 1/2, 1/2; --> 1 1 %e A137759 1/3, 5/6, 1/3; --> 1 3 5 1 3 %e A137759 1/4, 7/12, 7/12, 1/4; --> %e A137759 1/5, 9/20, 31/30, 9/20, 1/5; %Y A137759 Cf. A003506, A007622, A046201, A046204, A046205, A046206, A046208, A046212, A137752, A137753, A137754, A137755, A137756, A137757, A137758. %K A137759 frac,nonn,tabf,less %O A137759 1,6 %A A137759 _Mohammad K. Azarian_, Feb 11 2008