MathDB

Let

A_1=0

and

A_2=1

. For

n>2

, the number

A_n

is defined by concatenating the decimal expansions of

A_{n-1}

and

A_{n-2}

from left to right. For example

A_3=A_2A_1=10

A_4=A_3A_2=101

A_5=A_4A_3=10110

, and so forth. Determine all

n

such that

11

divides

A_n

Problem Statement