If A=(1101)A = \begin{pmatrix} 1 & 1 \\ 0 & 1 \end{pmatrix}A=(1011), what is the general form of AnA^nAn for any positive integer nnn?
(1n01)\begin{pmatrix} 1 & n \\ 0 & 1 \end{pmatrix}(10n1)
(12n01)\begin{pmatrix} 1 & 2^n \\ 0 & 1 \end{pmatrix}(102n1)
(1n201)\begin{pmatrix} 1 & n^2 \\ 0 & 1 \end{pmatrix}(10n21)
(1n(n+1)/201)\begin{pmatrix} 1 & n(n+1)/2 \\ 0 & 1 \end{pmatrix}(10n(n+1)/21)