%I #23 Sep 08 2022 08:45:50
%S 0,1,2,2,2,3,3,3,4,4,4,4,4,5,5,5,5,5,6,6,6,6,6,6,6,7,7,7,7,7,7,7,8,8,
%T 8,8,8,8,8,8,8,9,9,9,9,9,9,9,9,9,10,10,10,10,10,10,10,10,10,10,10,11,
%U 11,11,11,11,11,11,11,11,11,11,12,12,12
%N a(n) = floor(sqrt(2*n)).
%C If k is even, k appears k+1 times; if k is odd, k appears k times. - _N. J. A. Sloane_, Jan 25 2021
%H N. J. A. Sloane, <a href="/A172471/b172471.txt">Table of n, a(n) for n = 0..20000</a> [First 10000 terms from Vincenzo Librandi]
%F a(n) = A000196(2*n). - _R. J. Mathar_, Jul 06 2010
%t Table[Floor[Sqrt[2n]],{n,0,80}]
%o (Magma) [Floor(Sqrt(2*n)) : n in [0..80]];
%o (Haskell)
%o a172471 = a000196 . (* 2) -- _Reinhard Zumkeller_, Feb 12 2012
%o (PARI) for(n=0,50, print1(floor(sqrt(2*n)), ", ")) \\ _G. C. Greubel_, Jul 06 2017
%Y Cf. A000196, A003056, A103128, A005843.
%K nonn,easy
%O 0,3
%A _Vincenzo Librandi_, Feb 04 2010