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 A046204 #10 Jul 02 2025 16:01:56 %S A046204 2,6,4,12,20,30,60,42,140,8,56,168,280,72,252,504,630,10,90,360,840, %T A046204 1260,110,1320,2310,2772,132,660,1980,3960,5544,156,858,2860,10296, %U A046204 12012,14,182,1092,4004,10010,18018,24024,210,5460,30030,51480,16,240 %N A046204 Distinct even numbers in the triangle of denominators in Leibniz's Harmonic Triangle. %D A046204 L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 83, Problem 25. %e A046204 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 A046204 Cf. A003506. %K A046204 tabf,nonn,easy %O A046204 1,1 %A A046204 _Mohammad K. Azarian_ %E A046204 More terms from _James Sellers_, Dec 13 1999