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a(n) = largest multiple of n which is < exp(n).
4

%I #21 Nov 11 2014 18:18:38

%S 2,6,18,52,145,402,1092,2976,8100,22020,59873,162744,442403,1202600,

%T 3269010,8886096,24154943,65659968,178482295,485165180,1318815729,

%U 3584912826,9744803438,26489122128,72004899325,195729609426

%N a(n) = largest multiple of n which is < exp(n).

%F a(n) = n * floor(e^n/n) = n* A107316(n).

%p seq(n*floor(exp(n)/n), n=1..30); # _Robert Israel_, Nov 09 2014

%t f[n_] := n*Floor[Exp[n]/n];Array[f, 28] (* _Ray Chandler_, Feb 19 2007 *)

%t f[n_] := -First@ Mod[ Exp[n], n]; Array[f, 27] (* _Robert G. Wilson v_, Feb 19 2007 *)

%Y Cf. A128105, A107316.

%K nonn

%O 1,1

%A _Leroy Quet_, Feb 14 2007

%E Extended by _Robert G. Wilson v_ and _Ray Chandler_, Feb 19 2007