a280172_list :: [Integer]
a280172_list = map f [1..] where
  f n = head $ [1..] \\ map a280172 (rookIndices n)

-- Indices of the array that are above or to the left of n.
a280172_list :: [Integer]
a280172_list = map f [1..] where
  f n = head $ [1..] \\ map a280172 (rookIndices n)

-- Indices of the array that are above or to the left of n.
a280172_list = map f [1..] where
  f n = head $ [1..] \\ map a280172 (rookIndices n)

-- Indices of the array that are above or to the left of n.