Button of mobile phone

$\begin{array}{c}D 1 \ 2 \ 3 \\ 6 \ 5 \ 4 \\ 7 \ 8 \ 9 \\ 12 \ 11 \ 10 \\ \ldots \end{array}$

As the series goes continuous , then the number which would come in the 678th row would be $(678\times 3) , (678\times 3 -1)$ and $(678\times 3 - 2)$ .

So, in the odd row, the sequence is going front , whereas in even row the sequence is reversed. Thus, 678 is a even number and the number should be reversed. Our desired answer is

$2034, 2033, 2032$