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 A095252 #11 Jul 22 2024 14:36:56
%S A095252 1,4,17,65,233,808,2766,9362,31426,104822,1054033,11005043,114547418,
%T A095252 1188747707,12305003905,127088210000,1310019623181,13480213329659,
%U A095252 138498072735374,1420979139942389,14560878466498901,149036972532711329,1523880579042109897
%N A095252 a(n) = floor(sqrt{concatenation n,(n-1),...,3,2,1}).
%C A095252 a(n) = floor(sqrt(A000422(n))). - _Stefan Steinerberger_, May 05 2007
%e A095252 a(4) = floor(sqrt(4321)) = 65.
%p A095252 a:= n-> floor(sqrt(parse(cat((n-i)$i=0..n-1)))):
%p A095252 seq(a(n), n=1..30); # _Alois P. Heinz_, Aug 26 2015
%t A095252 Table[Floor[Sqrt[FromDigits[Flatten[Table[IntegerDigits[i],{i,n,1,-1}]]]]],{n,1,25}] (* _Stefan Steinerberger_, May 05 2007 *)
%t A095252 Table[Floor[Sqrt[FromDigits[Flatten[IntegerDigits/@Range[n,1,-1]]]]],{n,25}] (* _Harvey P. Dale_, Jul 22 2024 *)
%Y A095252 Cf. A068995.
%K A095252 base,easy,nonn,less
%O A095252 1,2
%A A095252 _Amarnath Murthy_, Jun 17 2004
%E A095252 More terms from _Stefan Steinerberger_, May 05 2007