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 A095253 #9 Mar 22 2020 23:35:48
%S A095253 1,4,6,8,8,9,9,9,9,10,12,14,17,19,22,24,26,28,30,32,34,36,38,39,41,42,
%T A095253 44,45,46,48,49,50,51,52,53,54,55,56,57,58,59,59,60,61,61,62,63,63,64,
%U A095253 65,65,66,66,67,67,68,68,69,69,70,70,71,71,71,72,72,72
%N A095253 a(n) = floor(concatenation(n,(n-1),...,3,2,1)^(1/n)).
%e A095253 a(4) = floor(4321^(1/4)) = 8.
%t A095253 Table[Floor[Surd[FromDigits[Flatten[IntegerDigits/@Range[n,1,-1]]],n]],{n,80}] (* _Harvey P. Dale_, Apr 21 2014 *)
%o A095253 (PARI) a(n) = {my(t=n); forstep(k=n-1, 1, -1, t=t*10^#Str(k)+k); sqrtnint(t, n); } \\ _Jinyuan Wang_, Mar 22 2020
%Y A095253 Cf. A068995, A095254.
%K A095253 nonn,base
%O A095253 1,2
%A A095253 _Amarnath Murthy_, Jun 17 2004
%E A095253 More terms from _Harvey P. Dale_, Apr 21 2014