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 A051549 #13 Dec 11 2024 08:38:15
%S A051549 1,1,3,12,84,84,84,168,840,10920,32760,32760,32760,32760,32760,32760,
%T A051549 1015560,1015560,1015560,1015560,1015560,4062240,4062240,4062240,
%U A051549 4062240,4062240,4062240,4062240,4062240,4062240,4062240,4062240,4062240,4062240,12186720
%N A051549 a(n) = LCM { sigma(1), ..., sigma(n) }.
%H A051549 Alois P. Heinz, <a href="/A051549/b051549.txt">Table of n, a(n) for n = 0..10000</a>
%p A051549 a:= proc(n) option remember; `if`(n=0, 1,
%p A051549 ilcm(a(n-1), numtheory[sigma](n)))
%p A051549 end:
%p A051549 seq(a(n), n=0..35); # _Alois P. Heinz_, Dec 11 2024
%t A051549 nn=40;With[{sig=DivisorSigma[1,Range[nn]]},Table[LCM@@Take[sig,n],{n,nn}]] (* _Harvey P. Dale_, Nov 15 2013 *)
%Y A051549 Cf. A000203.
%K A051549 nonn
%O A051549 0,3
%A A051549 _N. J. A. Sloane_
%E A051549 a(0)=1 inserted by _Alois P. Heinz_, Dec 11 2024