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 A075142 #3 Mar 30 2012 17:22:26
%S A075142 3,24,312,936,21528,150696,1657656,31495464,1354304952,2708609904,
%T A075142 143556324912,4163133422448,1387711140816,23591089393872,
%U A075142 1722149525752656,574049841917552,47646136879156816,4331466989014256
%N A075142 Denominator of the generalized harmonic number H(n,5,3).
%C A075142 The numerators are in A075141. See A075135 for more details.
%t A075142 a=5; b=3; maxN=20; s=0; Denominator[Table[s+=1/(a n + b), {n, 0, maxN-1}]]
%Y A075142 Cf. A075135, A075141.
%K A075142 easy,frac,nonn
%O A075142 1,1
%A A075142 _T. D. Noe_, Sep 04 2002