Question 901315
There are two patterns
2=4=6=8===10==12===14====16
=4=8=16=32==64==128==256===512
0, 2, 2, 4, 4, 8, 6, 16, 8, 32, 10, 64, 12, 128, 14, 256, 16, 512, 18, 1024, ...