%I
%S 1,2,4,6,8,9,11,12,14,16,18,19,21,23,24,26,28,30,31,33,35,36,38,40,42,
%T 43,45,47,48,50,52,54,55,57,59,61,62,64,66,68,69,71,73,75,76,78,80,82,
%U 84,85,87,89,91,92,94,96,98,99,101,103,105,106,108,110,112,114,115,117
%N a(n) is the smallest value k for which k!! >= n!.
%e a(6)=9 since m!!<6! for m<9, while 9!!>=6!.
%t Module[{df=Table[{i,i!!},{i,200}]},Transpose[Table[SelectFirst[df, #[[2]]>= n!&],{n,100}]][[1]]] (* _Harvey P. Dale_, Nov 05 2015 *)
%K easy,nonn
%O 1,2
%A _Giovanni Resta_, Feb 16 2006
