A192676 - OEIS

%I #7 Apr 04 2024 16:41:07

%S 1,0,1,1,3,6,16,43,121,365,1155,3832,13274,47862,179084,693589,

%T 2774358,11438972,48531450,211543687,946052129,4335355493,20334619731,

%U 97521410321,477755388567,2388776942837,12180420245150,63291320166423,334906186618646,1803525009870353

%N Floor-Sqrt transform of derangement numbers (A000166).

%F a(n) = floor(sqrt(derangements(n))).

%t FSFromExpSeries[f_,x_,n_] := Map[Floor[Sqrt[#]]&,CoefficientList[Series[f,{x,0,n}],x]Table[k!,{k,0,n}]]

%t FSFromExpSeries[Exp[-x]/(1-x),x,100]

%Y Cf. A000166.

%K nonn

%O 0,5

%A _Emanuele Munarini_, Jul 07 2011