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 A074043 #8 Jan 06 2025 20:25:40
%S A074043 3,15,15,105,1155,15015,255255,4849845,140645505,4360010655,
%T A074043 178760436855,7686698784765,453515228301135,27664428926369235,
%U A074043 1964174453772215685,143384735125371745005,14481858247662546245505
%N A074043 Denominator of Sum_{k=1..n} 1/A077800(k), numerator=A074042.
%C A074043 For n>2, a(n) = A048599(n-1).
%C A074043 A074042(n)/a(n) -> Brun's constant (A065421).
%Y A074043 Essentially the same as A048599.
%K A074043 nonn,frac
%O A074043 1,1
%A A074043 _Reinhard Zumkeller_, Aug 13 2002
%E A074043 Edited by _Max Alekseyev_, May 10 2009