Lista 3 - 1.37

#This algorithm was crated by Lucas Pereira Torres de Araujo
#Lista 3 - FUP's Class - 2016.1
#Item 1.37

print "Sendo a seguinte sequencia:\nN! / 0! - (N-1)! / 2! + (N-2)! / 4! - (N-3)! / 6! + ... 0! / (2N)!"
n = input("Digite o valor de N: ")
soma = float(0)

for i in xrange(0, n):
    fatn = 1
    for j in xrange(2, n-i):
        fatn = fatn*j

    fatd = 1
    for j in xrange(2, 2*i):
        fatd = fatd*j

    r = fatn/fatd
    r = float(r)

    if i%2 == 1:
        print i+1,"o. - termo =", r
        soma = soma + r
    else:
        print i+1,"o. - termo =", r
        soma = soma - r

print "Resultado =", soma