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 A191778 #10 Dec 10 2013 17:31:50
%S A191778 1,4,24,48,480,960,13440,26880,161280,322560,7096320,14192640,
%T A191778 369008640,738017280,1476034560,2952069120,100370350080,200740700160,
%U A191778 7628146606080,15256293212160,30512586424320,61025172848640,2807157951037440,5614315902074880,56143159020748800
%N A191778 a(1) = 1; a(n)= 2*lcm(n, a(n - 1)).
%C A191778 n and a(n-1) divide a(n).
%t A191778 a[1] = 1; a[n_] := a[n]=2 LCM (n, a[n - 1]);Table[a[n],{n,100}]
%t A191778 RecurrenceTable[{a[1]==1,a[n]==2*LCM[n,a[n-1]]},a,{n,30}] (* _Harvey P. Dale_, Dec 10 2013 *)
%K A191778 nonn
%O A191778 1,2
%A A191778 _José María Grau Ribas_, Jun 16 2011