What are the next items of this sequence?

$1101$, $31$, $21$, $15$, $13$, $\dots$


1 Answer 1


The numbers represent

Different bases. The bases increase by two. 1101 base2 is equal to 31 base4. 31 base4 is equal to 21 base6. 21 base6 is equal to 15 base8. 15 base8 is equal 13 base10.

So the next numbers are equal to

11(13 base10 is equal to 11 base12), D(11 base12 is equal to D base14), D(D base14 is equal to D base16), etc..


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