Create an 8 by merging two 4's.
Create a 4 by merging two 2's.
Create a 16 by merging two 8's.
Create a 32 by merging two 16's.
Create a 128 by merging two 64's.
Create a 64 by merging two 32's.
Create a 256 by merging two 128's.
Create a 512 by merging two 256's.
Create a 2048 by merging two 1024's.
Create a 1024 by merging two 512's.