solver.sagews

class VariableGenerator(object):
    def __init__(self, prefix):
        self.__prefix = prefix

    @cached_method    
    def __getitem__(self, key):
        return SR.var("%s%s"%(self.__prefix,key))
a=VariableGenerator('a')
answers={}

def aa(n):
    if n in answers:
        return answers[n]
    if n <= 30:
        answers[n] = a[n]
        return a[n]
    elif n <= 33:
        answers[n] = aa(n-31)
        return answers[n]
    else:
        answers[n] =  aa(n-31) + aa(n-3)
        return answers[n]

R=IntegerModRing(2**32)
def eq2vec(eq):
    return [eq.coefficient(a[i]) for i in range(31)]
V = [eq2vec(aa(344 + i)) for i in range(31)]
M = Matrix(R, V)
IM = M.inverse()
IM[0]
map(lambda x: Integer(x) if x < 2**31 else Integer(x) - 2**32, IM[0])