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 A046206 #10 Jul 02 2025 16:01:56 %S A046206 1,1,2,1,2,1,3,1,6,1,3,1,4,1,12,1,12,1,4,1,5,1,20,1,30,1,20,1,5,1,6,1, %T A046206 30,1,60,1,60,1,30,1,6,1,7,1,42,1,105,1,140,1,105,1,42,1,7,1,8,1,56,1, %U A046206 168,1,280,1,280,1,168,1,56,1,8,1,9,1,72,1,252,1,504,1,630,1,504,1,252 %N A046206 In Leibniz's Harmonic Triangle, write denominator first and then numerator of each element. %D A046206 L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 83, Problem 25. %e A046206 1/1; 1/2, 1/2; 1/3, 1/6, 1/3; 1/4, 1/12, 1/12, 1/4; 1/5, 1/20, 1/30, 1/20, 1/5; ... %Y A046206 Cf. A003506. %K A046206 tabf,nonn,easy %O A046206 1,3 %A A046206 _Mohammad K. Azarian_ %E A046206 More terms from _James Sellers_, Dec 13 1999