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 A030691 #16 Oct 30 2018 10:31:01
%S A030691 5,16,21,55,63,154,17,40,201,10,23,113,257,27,609,295,307,148,1535,
%T A030691 342,164,1692,809,1793,397,878,90,428,944,4482,987,1008,1029,4872,107,
%U A030691 2349,5154,5247,2478,252,552,5609,5697,5785,2726,1284,2806,6131
%N A030691 Cube root of A030690.
%C A030691 Smallest m such that m^3 begins with n^2.
%H A030691 Zak Seidov, <a href="/A030691/b030691.txt">Table of n, a(n) for n = 1..1000</a>
%e A030691 a(4)=55 because 55^3=166375 begins with 4^2=16. - _Zak Seidov_, Oct 18 2011
%t A030691 s={}; Do[If[n==3, AppendTo[s,21], k=1; While[(ra=Range[Ceiling[(n^2*10^k)^(1/3)], Floor[((n^2+1)*10^k)^(1/3)]]) == {}, k++]; AppendTo[s, ra[[1]]]], {n,100}]; s (* _Zak Seidov_, Oct 18 2011 *)
%K A030691 nonn,base
%O A030691 1,1
%A A030691 _Patrick De Geest_