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%I A103681 #13 Apr 07 2013 10:28:18
%S A103681 0,1,2,3,4,5,6,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,
%T A103681 27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,
%U A103681 50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73
%N A103681 Numbers m such that in binary representation m! doesn't contain 7!.
%C A103681 Complement of A103680: A103675(a(n))=0, A103675(A103680(n))=1.
%C A103681 Last term is probably 5153, since all numbers from 5154 to 5*10^5 do not belong to the sequence. - _Giovanni Resta_, Apr 07 2013
%H A103681 <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>
%H A103681 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%o A103681 (PARI) is(n)=n=n!; while(n>5039, my(e=valuation(n, 2), e1=valuation((n>>=e)+1, 2)); n>>=e1; if(e>3 && e1==2 && bitand(n, 127)==78, return(0))); 1 \\ _Charles R Greathouse IV_, Apr 07 2013
%Y A103681 Cf. A102730, A036603, A007088, A000142, A103677, A103679.
%K A103681 base,nonn
%O A103681 1,3
%A A103681 _Reinhard Zumkeller_, Feb 12 2005

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