https://qiitadon.com/@nabetani/112838 の素朴な解答

multi-palidromic-number.scala

def radix(d: Int, n: Int): List[Int] = {
  def loop(x: Int): List[Int] = 
    if (x == 0) Nil else { val a = x / d; val b = x % d; b :: loop(a) }
  loop(n).reverse
}

def isPalin(ns: List[Int]): Boolean = ns == ns.reverse

def isMultiPalin(n: Int): Boolean =
  (2 to n).toList.map(radix(_, n)).count(xs => xs.length > 2 && isPalin(xs)) >= 2

def solve(n: Int): Int = if (isMultiPalin(n)) n else solve(n+1)

println(List(1,399,99873).map(solve(_))) // List(17, 400, 99876)