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