Calculate number of items in a pyramid from number in its base

gistfile1.scala

def pyramid(base: Int): Int = {

    def p(b: Int, acc: Int): Int = {
        if (b < 1) {
            return acc
        } else {
            val n = acc + b - 1
            p(b - 1, n)
        }
    }

    p(base, base)
}