A171944 - OEIS

%I #15 Jul 11 2019 14:44:35

%S 0,2,3,5,7,8,9,11,12,13,15,17,19,20,21,23,25,27,28,29,31,32,33,35,36,

%T 37,39,41,43,44,45,47,48,49,51,52,53,55,57,59,60,61,63,65,67,68,69,71,

%U 73,75,76,77,79,80,81,83,84,85,87,89,91,92,93,95,97,99,100,101,103,105

%N N-positions for game of misere version of Mark.

%H Aviezri S. Fraenkel, <a href="http://dx.doi.org/10.1016/j.disc.2011.03.032">The vile, dopey, evil and odious game players</a>, Discrete Math. 312 (1) (2012) 42-46.

%p A17194X_list := proc(lim, X)

%p local n, d, S, A;

%p S := {1}; A := NULL;

%p for n from 1 to lim do

%p   d := numtheory[divisors](n);

%p   if d minus S <> {n} then

%p      A := A,`if`(X=5,n,iquo(n,2));

%p      S := S union d;

%p   fi

%p od; A end:

%p # A17194X_list(lim,4) gives A171944_list(lim);

%p # A17194X_list(lim,5) gives A171945_list(lim).

%p - _Peter Luschny_, Dec 28 2010

%t lim = 210; S = {1}; A = {};

%t Do[d = Divisors[n]; If[Complement[d, S] != {n}, A = Append[A, Quotient[n, 2]]; S = Union[S, d]], {n, 1, lim}];

%t A (* _Jean-François Alcover_, Jul 11 2019, after _Peter Luschny_ *)

%Y Complement of A171945. Apart from initial term, same as A053661.

%K nonn,easy

%O 1,2

%A _N. J. A. Sloane_, Oct 29 2010