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 A336401 #18 Aug 17 2020 13:37:21
%S A336401 1,10,102,1020,10200,102000,102000360,1020003600,10200036001680,
%T A336401 102000360016800,10200036001680035280,102000360016800352800,
%U A336401 102000360016800352800332640,1020003600168003528003326400
%N A336401 a(n) = a(n-1) concatenated with the smallest number k, such that a(n) is divisible by lcm(1..n).
%o A336401 (PARI) a(n)={if(n==1,return(1));for(n1=0,oo,k=eval(concat(Str(a(n-1)),n1));n2=0;for(n3=1,n,if(k%n3==0,n2+=1;if(n2==n,return(k)))))};
%Y A336401 Cf. A045874, A078282, A078283, A214437, A336399.
%K A336401 base,nonn
%O A336401 1,2
%A A336401 _Eder Vanzei_, Jul 20 2020