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a(n) = the largest multiple of {the number of divisors of n} that is <= n.
2

%I #12 Feb 21 2019 23:10:34

%S 1,2,2,3,4,4,6,8,9,8,10,12,12,12,12,15,16,18,18,18,20,20,22,24,24,24,

%T 24,24,28,24,30,30,32,32,32,36,36,36,36,40,40,40,42,42,42,44,46,40,48,

%U 48,48,48,52,48,52,56,56,56,58,60,60,60,60,63,64,64,66,66,68,64,70,72,72

%N a(n) = the largest multiple of {the number of divisors of n} that is <= n.

%H Enrique Pérez Herrero, <a href="/A161654/b161654.txt">Table of n, a(n) for n = 1..5000</a>

%F a(n) = floor(n/tau(n)) = floor(n/A000005(n)). - _Enrique Pérez Herrero_, Apr 28 2012

%p with(numtheory): a := proc (n) local k: for k while 0 <= n-k*tau(n) do end do: (k-1)*tau(n) end proc; seq(a(n), n = 1 .. 75); # _Emeric Deutsch_, Jun 20 2009

%t A161654[n_]:=Floor[n,DivisorSigma[0,n]]; Table[A161654[n],{n,1,100}] (* _Enrique Pérez Herrero_, Apr 28 2012 *)

%Y Cf. A161655, A000005.

%K nonn

%O 1,2

%A _Leroy Quet_, Jun 15 2009

%E More terms from _Emeric Deutsch_, Jun 20 2009