mem = dict() #global dictionary for memoization

def expressible(m,digits,k):
    if (m,digits,k) in mem:
        return mem[(m,digits,k)]
    elif m == 0 and k == 0:
        mem[(m,digits,k)] = True
        return True
    elif len(digits) == 0 or k > len(digits):
        mem[(m,digits,k)] = False
        return False
    else:
        for d in set(digits):
            i = int(d)
            remaining = digits.replace(d,'',1)
            if expressible(m + i,remaining, k-1) or expressible(m - i,remaining, k-1):
                mem[(m,digits,k)] = True
                return True
        #if we reach here:
        mem[(m,digits,k)] = False
        return False

def selfContained(a,b):
    nums = []
    for n in range(a,b+1):
        digits = ''.join(sorted(str(n)))
        contained = True #until a counter-example found
        for d in set(digits):
            i = int(d)
            remaining = digits.replace(d,'',1)
            if not expressible(i,remaining,2):
                contained = False
                break
            if not contained: break
        #if we reach here and contained is still true, no counterxamples, so:
        if contained: nums.append(n)
    mem.clear()
    return nums

>>> selfContained(1,360)
[101, 110, 112, 121, 123, 132, 134, 143, 145, 154, 156, 165, 167, 176, 178, 187, 189, 198, 202, 211, 213, 220, 224, 231, 235, 242, 246, 253, 257, 264, 268, 275, 279, 286, 297, 303, 312, 314, 321, 325, 330, 336, 341, 347, 352, 358]

nums = selfContained(0,1000000)

999909, 999918, 999927, 999936, 999945, 999954, 999963, 999972, 999981, 999990