# Use 0 1 2 3 4 to form 9 3-digit numbers

Use $$0, 1, 2, 3, 4$$ to make the any of these numbers:

$$331, 333, 435, 452, 455, 458, 461, 469, 470$$

1. You must use all $$5$$ digits $$0, 1, 2, 3, 4$$ each exactly once. You can make multi-digit numbers out of the numbers, e.g. $$120$$ or $$42$$.

2. The square function may NOT be used. Nor may the cube, raise to a fourth power, or any other function that raises a number to a specific power. You may use the ^ operation if you use a digit, for example, $$[(10 + 3)^2 +4]$$ is acceptable because $$0, 1, 2, 3, 4$$ is used. However, $$[(10 + 3)^2 +4+2]$$ can't be used because it uses an extra $$2$$.

3. The integer function may NOT be used. Nor may the round, floor, ceiling, repeating or concatenation symbol, or truncate functions.

4. The square root, multi factorial, subfactorial and decimal point may NOT be used.

5. $$+, -, *, /, (), \text{^}, \text{and }!$$ (factorial) may be used for functions. Example: factorial may be used more than once, e.g. $$(3!)!=720$$ is acceptable.

From the numbers $$0 \text{ ~ } 500$$, those $$9$$ numbers above are the only ones I didn't get.

• So you are allowed to change around the order of the numbers?
– Duck
Jun 18, 2019 at 18:42
• yes correct, changing the order of the numbers is allowed. Jun 18, 2019 at 18:45
• Can we use combination or permutation operators? Jul 26, 2019 at 19:55
• Combination yes, permutation no Jul 26, 2019 at 20:02
• How will you choose who to give the bounty to? It looks like a lot of people contributed Jul 26, 2019 at 20:23

452

Using the bracket notation for the rising factorial:

$$(10^{(2)}+3)\times4=(10\cdot11+3)\times4=113\cdot4=452$$

• Do you think it's possible to actually prove it's impossible, somehow? Maybe using some size argument? Obviously it wouldn't be easy but would it be possible? Jul 28, 2019 at 15:06
• @im_so_meta_even_this_acronym; well, there's only a finite number of possibilities...
– JMP
Jul 28, 2019 at 19:29
• There aren't actually, factorial exists Jul 28, 2019 at 19:30
• @im_so_meta_even_this_acronym; but how is $4!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!$ going to be of use?
– JMP
Jul 28, 2019 at 19:32
• Well, it probably won't be but seems hard to prove, what if that number minus 2 divided by 3!!!!!!!!!!!!!!!!!!! or something was useful? (This clearly does not work by considering prime factors, but you get the point). Jul 28, 2019 at 19:54

470

$$4\times(3+2)!-10 = 470$$

455 (by @ThomasL)

$$(4!)^2-(3!-0!)!-1 = 455$$

333 (by @ripkoops)

$$213+(0!+4)! = 333$$

• I managed to get 455: (4!)^2-(3!-0!)!-1 = 576-120-1=455 Jun 20, 2019 at 20:47
• 333 = 213+(0!+4)! Jun 21, 2019 at 1:06
• ThomasL, ripkoops Thanks! I've aggregated these comment answers into the answer above Jun 25, 2019 at 16:25

Interpretation of the brackets as being the binomial coefficient I was able to get four more numbers 435, 458, 461, and 469:

$$435 = \binom{30}{2}\times1^4$$
$$458 = \binom{30}{2}+4!-1$$
$$461 = \binom{31}{2}-4+0$$
$$469 = \binom{31}{2}+4+0$$

• two numbers are left to crack: 331 and 452 Jun 27, 2019 at 20:17

EDIT: My original solutions were invalid, sorry for being a complete idiot.

New solution for 331:

$$\dbinom{2\cdot3!-1}{4}+0!$$

• well the OP doesn't say you can't use binomial...
– JMP
Jul 5, 2019 at 7:02
• I assumed it was ok as the OP used binomial in the post directly above mines. Just checking I didn't blatantly violate one of the rules again :) Jul 5, 2019 at 7:05
• I guess so then! I'd assumed binomial's were illegal otherwise you can get away with almost anything , but if the O says they're OK, then they must be!
– JMP
Jul 5, 2019 at 7:12

Some "almost-solutions" (with one of the digits repeated twice) for 452, the only number which remains unsolved at the time of posting (I'm posting this as ideas, because somebody may rework them):

with 2 zeroes: $$452=\binom{4!/2-0!}{3!}-10$$
with 2 ones: $$452=\binom{4!/2-1}{3!}-10$$
with 2 threes: $$452=(3!+1^0)\cdot2^{3!}+4$$
with 2 fours: $$452=\binom{10+2}{4}-43$$

# Possible for 452

I'm not sure whether this is allowed or not but here goes:

$$0!=1$$
$$1+1=2$$
$$3+2=5$$
$$concat(concat(4, 5), 2)$$

• sorry, but concat is not allowed as already mentioned in rule 3 Jul 26, 2019 at 20:08
• @ThomasL - Whoopsie! I must have missed that... Jul 26, 2019 at 20:12
• Don't worry I did this too before :P Jul 26, 2019 at 20:19