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!)
A140134 a(n)=2a(n-1) but when sum of digits of 2a(n-1) is greater than 9 take a(n) = largest number < 2a(n-1) which has sum of digits = 9. 0

%I #8 Oct 08 2012 15:52:18

%S 1,2,4,8,16,32,63,126,252,504,1008,2016,4032,8001,16002,32004,63000,

%T 126000,252000,504000,1008000,2016000,4032000,8001000,16002000,

%U 32004000,63000000,126000000,252000000,504000000,1008000000,2016000000

%N a(n)=2a(n-1) but when sum of digits of 2a(n-1) is greater than 9 take a(n) = largest number < 2a(n-1) which has sum of digits = 9.

%e a(12)=4032; 2*4032 = 8064; digit sum is 18; decrease until we get a number with digit sum 9, which is 8001; so a(13) = 8001. - From _N. J. A. Sloane_, Oct 08 2012

%Y Cf. A062259.

%K nonn,base

%O 0,2

%A _Paul Curtz_, Jun 15 2008

%E Keyword base added by _Reinhard Zumkeller_, Feb 25 2010

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 April 27 12:00 EDT 2024. Contains 372019 sequences. (Running on oeis4.)