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 A166447 #30 Jun 19 2024 09:32:14
%S A166447 0,1,2,6,8,10,12,21,24,27,30,33,36,52,56,60,64,68,72,76,80,105,110,
%T A166447 115,120,125,130,135,140,145,150,186,192,198,204,210,216,222,228,234,
%U A166447 240,246,252,301,308,315,322,329,336,343,350,357,364,371,378,385,392,456
%N A166447 a(n) = n*round(sqrt(n)).
%H A166447 G. C. Greubel, <a href="/A166447/b166447.txt">Table of n, a(n) for n = 0..999</a> [Offset shifted by _Georg Fischer_, Aug 30 2021]
%F A166447 a(n) = n*A000194(n). - _R. J. Mathar_, Nov 18 2009
%p A166447 seq(n*round(sqrt(n)), n=0..60); # _Georg Fischer_, Aug 28 2021
%p A166447 # second Maple program:
%p A166447 a:= n-> n*isqrt(n):
%p A166447 seq(a(n), n=0..60); # _Alois P. Heinz_, Aug 29 2021
%t A166447 Table[n Round[Sqrt[n]],{n,0,60}] (* _Harvey P. Dale_, Oct 30 2021 *)
%o A166447 (Magma) [n*Round(Sqrt(n)): n in [0..60]]; // _Vincenzo Librandi_, May 15 2016
%o A166447 (Python)
%o A166447 from math import isqrt
%o A166447 def A166447(n): return n*((m:=isqrt(n))+int(n-m*(m+1)>=1)) # _Chai Wah Wu_, Jun 19 2024
%K A166447 nonn,easy
%O A166447 0,3
%A A166447 _Vladimir Joseph Stephan Orlovsky_, Oct 13 2009
%E A166447 Offset corrected by _Georg Fischer_, Aug 28 2021