%I #15 Nov 16 2017 15:50:17

%S 0,1,2,3,4,6,7,8,9,11,13,14,15,16,17,18,19,20,21,24,26,28,30,31,32,36,

%T 46,53,58,65

%N Numbers m such that in binary representation m! doesn't contain 5!.

%C Conjecture: there are no further terms;

%C complement of A103676: A103673(a(n))=0, A103673(A103676(n))=1.

%H <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>

%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>

%o (PARI) is(n)=n=n!; while(n>119, my(e=valuation(n, 2), e1=valuation((n>>=e)+1, 2)); n>>=e1; if(e>2 && e1>3, return(0))); 1 \\ _Charles R Greathouse IV_, Apr 07 2013

%Y Cf. A102730, A036603, A007088, A000142, A103679, A103681.

%K nonn,base

%O 1,3

%A _Reinhard Zumkeller_, Feb 12 2005