RosettaCodeData/Task/Ackermann-function/R/ackermann-function-1.r

ackermann <- function(m, n) {
  if ( m == 0 ) {
    n+1
  } else if ( n == 0 ) {
    ackermann(m-1, 1)
  } else {
    ackermann(m-1, ackermann(m, n-1))
  }
}