.data
	n: .word 4

.text

main:
	la $a0, n
	lw $a0, 0($a0)

	addi $sp, $sp, -8
	sw $ra, 0($sp)
	sw $a0, 4($sp)

	jal T

	add $a0, $v0, $0
	addi $v0, $0, 1
	syscall

	lw $ra, 0($sp)
	lw $a0, 4($sp)
	addi $sp, $sp, 8
	jr $ra


T:
	addi $t1, $0, 3
	slt $t1, $a0, $t1
	beq $t1, $0, Else
	add $v0, $0, 1
	jr $ra

	Else:
		addi $sp, $sp, -20
		sw $ra, 0($sp)
		sw $s0, 4($sp)
		sw $s1, 8($sp)
		sw $s2, 12($sp)
		sw $s3, 16($sp)

		add $s3, $0, $0
		addi $a0, $a0, -1       # n -= 1
		add $s1, $a0, $0
		For:
			add $s0, $s3, $0
			addi $s3, $s3, 1
			add $a0, $s0, $0

			jal T
			mult $v0, $s0
			mflo $t0
			add $s2, $s2, $t0
			bne $s0, $s1, For

		add $v0, $0, $s2

		lw $ra, 0($sp)
		lw $s0, 4($sp)
		lw $s1, 8($sp)
		lw $s2, 12($sp)
		lw $s3, 16($sp)
		addi $sp, $sp, 20
		jr $ra

Versione C:

#include <stdio.h>

int c(int n, int count)
{
    if(n<3){return 1;}
    for(int x=0; x<=n-1; x++)
    {
        count += x*c(x, count);
    }
    return count;
}

int main()
{
    int n = 4;
    printf("%d", c(n, 0));
    return 0;
}