A201024 Composite numbers whose multiplicative digital root is 9.

9, 33, 91, 119, 133, 1119, 1133, 1191, 1313, 1331, 1911, 3113, 3131, 3311, 9111, 11133, 11191, 11313, 11331, 11911, 13113, 13131, 13311, 19111, 31113, 31131, 31311, 33111, 91111, 111133, 111313, 111331, 111911, 113113, 113311, 119111, 131131, 133111, 191111, 311113

Offset

1,1

Comments

Also composite numbers whose product of digits is 9. Complement of A107695 with respect to A034056.

Links

Table of n, a(n) for n=1..40.

Example

Number 133 is in sequence because 1*3*3=9.

Mathematica

Select[Range[320000], !PrimeQ[#]&&Times@@IntegerDigits[#]==9&] (* Harvey P. Dale, Aug 27 2012 *)

Crossrefs

Cf. A107695 (primes whose multiplicative digital root is 9), A034056 (numbers whose multiplicative digital root is 9).

Sequence in context: A020228 A005939 A020326 * A228170 A112888 A048479

Adjacent sequences: A201021 A201022 A201023 * A201025 A201026 A201027

Keyword

nonn,base

Author

Jaroslav Krizek, Nov 25 2011

Status

approved