A103677 - OEIS

A103677

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

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, 46, 53, 58, 65

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OFFSET

1,3

COMMENTS

Conjecture: there are no further terms;

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

LINKS

Table of n, a(n) for n=1..30.

Index entries for sequences related to factorial numbers

Index entries for sequences related to binary expansion of n

PROG

(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

CROSSREFS

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

Sequence in context: A028237 A194463 A140467 * A087919 A113508 A059325

Adjacent sequences: A103674 A103675 A103676 * A103678 A103679 A103680

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, Feb 12 2005

STATUS

approved