perplexus.info :: Numbers : six and thirteen

six and thirteen (Posted on 2018-03-15)

Part one:

Compose number 6 with each digit using the digit only three times (Ex: 6=2+2+2) Allowed basic operations (+,-,*,/), sqrt and factorial (no others).

Part two:

Get number 13 using only number 2 three times. Allowed basic and not-basic operations.

No Solution Yet Submitted by armando

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contribution to different ways

| Comment 7 of 9 |

using function sigma (sum of divisors of an integer)

sigma (4) = 1+2+4 = 7

sigma (9) = 1+3+9 = 13

sigma (sigma (2+2) + 2) = 13

Posted by armando on 2018-03-16 04:51:44

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