Disarium numbers

func is_disarium(n) {
    n.digits.flip.sum_kv{|k,d| d**(k+1) } == n
}
 
say 18.by(is_disarium)

Output:

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 89, 135, 175, 518, 598, 1306, 1676, 2427]