cp's OEIS Frontend

A103675 a(n) = 1 if the binary representation of n! contains 7! (bit string "1001110110000"), otherwise a(n) = 0.

%I A103675 #18 Dec 26 2018 16:53:49
%S A103675 0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%T A103675 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U A103675 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0
%N A103675 a(n) = 1 if the binary representation of n! contains 7! (bit string "1001110110000"), otherwise a(n) = 0.
%C A103675 a(A103680(n)) = 1, a(A103681(n)) = 0.
%C A103675 Probably a(5153) is the last zero term. a(n) = 1 for n from 5154 to 5*10^5. - _Giovanni Resta_, Apr 07 2013
%H A103675 Antti Karttunen, <a href="/A103675/b103675.txt">Table of n, a(n) for n = 0..10080</a>
%H A103675 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%H A103675 <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>
%H A103675 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%o A103675 (PARI) a(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(1))); 0 \\ _Charles R Greathouse IV_, Apr 07 2013
%Y A103675 Cf. A000142, A007088, A102730, A036603, A103673, A103674.
%K A103675 base,nonn
%O A103675 0,1
%A A103675 _Reinhard Zumkeller_, Feb 12 2005
%E A103675 Name edited by _Antti Karttunen_, Dec 24 2018