Puzzle 49: What’s to the West?

Fillomino Borders.
Divide the grid into polyominoes such that no two polyominoes with the same area touch each other, and put a number in each square indicating the area of the polyomino it is contained in. In addition, these clues exist at the border and must be satisfied by the two numbers that each clue touch:
– Inequality signs: The inequality must be satisfied (the number pointed by the pointy part must be smaller than the other)
– Black circles: One of the numbers must be exactly twice of the other number
– White circles: The numbers must be consecutive
– Thin borders: The two numbers must be equal
– Thick borders: The two numbers must be different

What’s to the west? Sky doesn’t know. Is it a treasure? An island yet to be discovered? A source of puzzles? No one knows. But one thing for sure, Sky has made this medium puzzle as a teaser.

Puzzle 49: What’s to the West?
Fillomino Borders

Mostly an introduction to Fillomino Borders, a mesh-up of three Fillomino variants and an addition of “no-border” clue to counter Fillomino Walls’ “border” clue. Also a very obvious theme, although I began the construction from the outer ring before going for the cross walls and the remaining theme. I might revisit this trick again.

Also, if you have read my Flygrass Town article, you should know what’s to the west.