Wolfram Mathematica 34 29 bytes
2#~Drop~2==MovingMap[Tr,#,2]&
–5 bytes from @att
[Included the [3,4,6,10,16] and [1,1,1,2] falsey test cases from Noodle9 and DLosc, respectively.]
Wolfram Mathematica
theorist
- 1.5k
- 6
- 12