[seqfan] Binary digits change sequences

Ali Sada pemd70 at yahoo.com
Tue Aug 13 15:27:54 CEST 2019

Hi Everyone,

Please see the sequences below. I just want to check if theywere “legitimate” to be added to OEIS. 

The definition “Number of digits that change when we multiplynatural numbers by 2 in the binary system” gives us: 


 (For example.101*10=1010. All 4 digits changed, so a(5)=4.)  

I couldn’t find this sequence. However, when I divided eachterm by 2, I got A069010 (except for the zero at the start.) 


Also, with the same definition but multiplying by 3instead of 2, I got 


Which is A007302, except for the initial zero again. 


When I repeated the definition, multiplying by 4 this time, Igot


Maybe I didn’t look well, but I couldn’t find this one evenwhen I divided by 2.
(Is multiplying by even numbers always gives us even numbers of digit changes? And if so,why?)   

I am working on multiplying by more numbers. I am alsoworking on base-3,4,5,… systems. 

I would appreciate any feedback.





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