I am considering a procedure in which it is useful to switch between bases and operate on a number in these different bases (take decimal truncations etc). What matters here is the actual sequnce of digits. Now at the end of an operation, I have a sequnce of digits corresponding to a number in base 3 say, and I wish now to express the sequence which is "the number corresponding to the sequnce written in base 3, now written in base 10". Is there a nice notation for this that I am not aware of?

# Is there a standard notation for ‘written in base a’

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## Best Answer

It's common to write $$ 13 = 111_3 . $$ With no subscript, the convention is that you have written the base $10$ expansion of the number.

You can safely use that notation, Just explain it to your reader the first time.

The base (the subscript) is written in base 10, so $$ A_{16} = 10 $$ and $$ 10_n = n . $$