A166447 - OEIS

%I #30 Jun 19 2024 09:32:14

%S 0,1,2,6,8,10,12,21,24,27,30,33,36,52,56,60,64,68,72,76,80,105,110,

%T 115,120,125,130,135,140,145,150,186,192,198,204,210,216,222,228,234,

%U 240,246,252,301,308,315,322,329,336,343,350,357,364,371,378,385,392,456

%N a(n) = n*round(sqrt(n)).

%H 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 a(n) = n*A000194(n). - _R. J. Mathar_, Nov 18 2009

%p seq(n*round(sqrt(n)), n=0..60); # _Georg Fischer_, Aug 28 2021

%p # second Maple program:

%p a:= n-> n*isqrt(n):

%p seq(a(n), n=0..60);  # _Alois P. Heinz_, Aug 29 2021

%t Table[n Round[Sqrt[n]],{n,0,60}] (* _Harvey P. Dale_, Oct 30 2021 *)

%o (Magma) [n*Round(Sqrt(n)): n in [0..60]]; // _Vincenzo Librandi_, May 15 2016

%o (Python)

%o from math import isqrt

%o def A166447(n): return n*((m:=isqrt(n))+int(n-m*(m+1)>=1)) # _Chai Wah Wu_, Jun 19 2024

%K nonn,easy

%O 0,3

%A _Vladimir Joseph Stephan Orlovsky_, Oct 13 2009

%E Offset corrected by _Georg Fischer_, Aug 28 2021