4323.sagews

divisors(220)

[1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 220]

divisors(284)

[1, 2, 4, 71, 142, 284]

1+2+4+71+142

220

1+2+4+5+10+11+20+22+44+55+110

284

divisors(28)

[1, 2, 4, 7, 14, 28]

1+2+4+7+14

28

sum(divisors(28))

56

var("n")
s(n)=sum(divisors(n))-n

Traceback (most recent call last): File "<stdin>", line 1, in <module> File "_sage_input_10.py", line 10, in <module> exec compile(u'open("___code___.py","w").write("# -*- coding: utf-8 -*-\\n" + _support_.preparse_worksheet_cell(base64.b64decode("dmFyKCJuIikKcyhuKT1zdW0oZGl2aXNvcnMobikpLW4="),globals())+"\\n"); execfile(os.path.abspath("___code___.py"))' + '\n', '', 'single') File "", line 1, in <module> File "/tmp/tmpVBYRUE/___code___.py", line 3, in <module> exec compile(u'__tmp__=var("n"); s = symbolic_expression(sum(divisors(n))-n).function(n)' + '\n', '', 'single') File "", line 1, in <module> File "/sagenb/sage_install/sage-4.8-sage.math.washington.edu-x86_64-Linux/local/lib/python2.6/site-packages/sage/rings/arith.py", line 1301, in divisors for p, e in f: TypeError: 'sage.symbolic.expression.Expression' object is not iterable

def s(n):
    list=divisors(n)
    total=sum(list)
    return total-n

s(28)

28

s(220)

284

s(284)

220

s(1184)

1210

s(1210)

1184

point([ (1, 2, 3),  (4, 5, 6),  (0, 1, 0),  (0, 0, 1)  ])

@interact 
def f(n=[0..4], s=(1..5), y=(0,1,0.01)):
    show(plot(sin(n+x^s)+y, -pi, pi))

n  s  y  [removed] [removed] [removed] [removed]

@interact 
def myhelper(x0=(1,10,0.01)):
    g(x)=sqrt(x)
    gprime(x)=diff(g(x))
    slope=gprime(x0)
    show(plot( g(x), 0, 10) + plot( slope*(x - x0) + g(x0), 0, 10, color='brown' ) + point( (x0, g(x0)) )  )

x0  [removed] [removed] [removed] [removed]

@interact 
def myhelper2(x0=(1,10,0.01), choice=[ "ln", "log", "ld" ]):
    if (choice=="ln"):
        g(x)=ln(x)
    elif (choice=="log"):
        g(x)=log(x, 10)
    elif (choice=="ld"):
        g(x)=log(x, 2)
    else:
        print("?!?!")
        g(x)=x
    gprime(x)=diff(g(x))
    slope=gprime(x0)
    show(plot( g(x), 0.5, 10) + plot( slope*(x - x0) + g(x0), 0.5, 10, color='brown' ) + point( (x0, g(x0)) )  )

x0  choice  [removed] [removed] [removed] [removed]