function printTriangle (n, i) {
  if (i === n) {
    console.log(Array.from({ length: i }, (_, i) => i + 1).join(' '))
    return
  }

  console.log(Array.from({ length: i }, (_, i) => i + 1).join(' '))
  printTriangle(n, i + 1)
  console.log(Array.from({ length: i }, (_, i) => i + 1).join(' '))
}

printTriangle(5, 1)