A103675 - OEIS

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A103675

If in binary representation n! contains 7! then 1 else 0.

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, 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, 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 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`0,1`
	COMMENTS	`a(A103680(n)) = 1, a(A103681(n)) = 0.` `Probably a(5153) is the last zero term. a(n) = 1 for n from 5154 to 5*10^5. - Giovanni Resta, Apr 07 2013`
	LINKS	`Table of n, a(n) for n=0..104.` `Index entries for characteristic functions` `Index entries for sequences related to factorial numbers` `Index entries for sequences related to binary expansion of n`
	PROG	`(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`
	CROSSREFS	`Cf. A102730, A036603, A007088, A000142, A103673, A103674.` `Sequence in context: A011705 A011704 A011717 * A144199 A144201 A175861` `Adjacent sequences: A103672 A103673 A103674 * A103676 A103677 A103678`
	KEYWORD	`base,nonn`
	AUTHOR	`Reinhard Zumkeller, Feb 12 2005`
	STATUS	`approved`

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Last modified May 22 14:05 EDT 2013. Contains 225550 sequences.