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 A018072 #34 May 31 2025 11:08:27
%S A018072 1,1,3,5,10,17,31,56,100,177,316,562,1000,1778,3162,5623,10000,17782,
%T A018072 31622,56234,100000,177827,316227,562341,1000000,1778279,3162277,
%U A018072 5623413,10000000,17782794,31622776,56234132,100000000,177827941,316227766,562341325,1000000000,1778279410
%N A018072 Powers of fourth root of 10 rounded down.
%H A018072 Vincenzo Librandi, <a href="/A018072/b018072.txt">Table of n, a(n) for n = 0..2000</a>
%e A018072 a(2) = 3 because 10^(2/4) = 10^(1/2) = sqrt(10) = 3.16228...
%e A018072 a(3) = 5 because 10^(3/4) = 5.62341...
%e A018072 a(4) = 10 because 10^(4/4) = 10^1 = 10.
%e A018072 a(5) = 17 because 10^(5/4) = 17.78279...
%t A018072 Table[Floor[10^(n/4)], {n, 0, 39}] (* _Alonso del Arte_, Jan 26 2013 *)
%t A018072 Floor[Surd[10,4]^Range[0,40]] (* _Harvey P. Dale_, Oct 26 2019 *)
%o A018072 (PARI) a(n)=sqrtint(sqrtint(10^n)) \\ _Charles R Greathouse IV_, Jan 27 2013
%o A018072 (Magma) [Floor(10^(n/4)): n in [0..37]]; // _Vincenzo Librandi_, May 30 2025
%Y A018072 Cf. A017934, A011007, A010467.
%K A018072 nonn,easy
%O A018072 0,3
%A A018072 _N. J. A. Sloane_
%E A018072 A few additional terms from _Alonso del Arte_, Jan 26 2013