login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A201024 Composite numbers whose multiplicative digital root is 9. 0

%I #9 Aug 27 2012 11:06:27

%S 9,33,91,119,133,1119,1133,1191,1313,1331,1911,3113,3131,3311,9111,

%T 11133,11191,11313,11331,11911,13113,13131,13311,19111,31113,31131,

%U 31311,33111,91111,111133,111313,111331,111911,113113,113311,119111,131131,133111,191111,311113

%N Composite numbers whose multiplicative digital root is 9.

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

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

%t Select[Range[320000],!PrimeQ[#]&&Times@@IntegerDigits[#]==9&] (* _Harvey P. Dale_, Aug 27 2012 *)

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

%K nonn,base

%O 1,1

%A _Jaroslav Krizek_, Nov 25 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 06:15 EDT 2024. Contains 371265 sequences. (Running on oeis4.)