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 A104357 #12 May 28 2018 17:24:56
%S A104357 0,1,5,11,59,179,1259,2519,7559,37799,415799,1247399,16216199,
%T A104357 113513399,567566999,1135133999,19297277999,57891833999,1099944845999,
%U A104357 5499724229999,38498069609999,423478765709999,9740011611329999
%N A104357 a(n) = A104350(n) - 1.
%H A104357 G. C. Greubel, <a href="/A104357/b104357.txt">Table of n, a(n) for n = 1..640</a>
%H A104357 R. Zumkeller, <a href="/A104350/a104350.txt">Products of largest prime factors of numbers <= n</a>
%F A104357 a(n) = (a(n-1) + 1) * A006530(n) - 1 for n>1, a(1) = 0;
%t A104357 A104350[n_] := Product[FactorInteger[k][[-1, 1]], {k, 1, n}]; Table[A104350[n] - 1, {n, 1, 50}] (* _G. C. Greubel_, May 09 2017 *)
%t A104357 FoldList[Times,Table[FactorInteger[n][[-1,1]],{n,30}]]-1 (* _Harvey P. Dale_, May 28 2018 *)
%Y A104357 Cf. A104358, A104359, A104360, A104361, A104362, A104363, A104365, A033312, A057588.
%K A104357 nonn
%O A104357 1,3
%A A104357 _Reinhard Zumkeller_, Mar 06 2005