Mapping of a series

61 Views Asked by At

I have been trying for a logic for mapping a series which is

8->15 maps to 0-7 24->31 maps t0 8-15 40->47 maps to 16-23

and so on . I am given this sequence and a constant number =8. I can do subtraction, addition, multiplication , division etc. with series numbers and constant number. Trying hard since yesterday, can anyone tell me it is even possible?

1

There are 1 best solutions below

1
On BEST ANSWER

Each number in your sequence on the left are precisely those numbers with a $1$ in the third digit (counting from the right) when represented in binary. (See http://oeis.org/A115419)

By considering the binary representation of your numbers, determine the result of your "mapping" by deleting the third digit. (By deleting, I mean completely remove it, not just replace it with zero).

E.g. $8$ which was $\color{red}{1}00_2$ becomes $00_2$ which is $0$ in decimal, $24$ which was $1\color{red}{1}00_2$ becomes $100_2$ which is $8$ in decimal, $29$ which was $11\color{red}{1}01_2$ becomes $1101_2$ which is $13$ in decimal, etc...

If you insist on this being notated with symbols rather than words, then we have $n\mapsto 8\lfloor\frac{n}{16}\rfloor + n-8\lfloor\frac{n}{8}\rfloor$