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 A274461 #18 Jun 26 2016 01:30:22
%S A274461 1,4,8,72,144,3600,10800,21600,1058400,2116800,6350400,768398400,
%T A274461 3841992000,7683984000,1298593296000,3895779888000,7791559776000,
%U A274461 2251760775264000,15762325426848000,5690199479092128000,11380398958184256000,6020231048879471424000,30101155244397357120000,90303465733192071360000
%N A274461 Least common multiple of first n proper prime powers.
%C A274461 Squares in this sequence include a(0)=1^2, a(1)=2^2, a(4)=12^2, a(5)=60^2, a(10)=2520^2, and a(11)=27720^2. Are there any more?
%C A274461 All terms in this sequence are powerful numbers (A001694).
%t A274461 t = Join[{1}, Select[Range@ 1000, Min@ FactorInteger[#][[All, 2]] > 1 &]]; Union@ Table[LCM @@ t[[1 ;; n]], {n, 45}] (* _Michael De Vlieger_, Jun 24 2016, after _Harvey P. Dale_ at A001694 *)
%o A274461 (PARI) alist(n)=my(pp=0,x=1);vector(n,k,while(isprimepower(pp++)<2&&pp!=1,0); x=lcm(x, pp))
%Y A274461 Cf. A051451, A246547, A001694.
%K A274461 nonn
%O A274461 0,2
%A A274461 _Franklin T. Adams-Watters_, Jun 23 2016