Talk:Sum-product number

Latest comment: 8 years ago by Steveschwei in topic 220 in base 16 has to be wrong.

Just a little note: In his proof Puzio used m to represent Length[IntegerDigits[n, b]]. Here I used l for that purpose because that's what PrimeFan used when he started the article (he was thinking of "length," I presume). Anton Mravcek 22:57, 21 March 2006 (UTC)Reply

The l has the problem that it looks like 1. The problem with m is that I don't know how to give it a mnemonic meaning that makes sense here. If anyone else can, then they should change all the ls to ms. PrimeFan 14:31, 22 March 2006 (UTC)Reply

Hi, I would like to know, if there is a name for the sum of 4 didget numbers like:2649=21 also same as 9462=21 what is that called? —Preceding unsigned comment added by 68.84.68.238 (talk) 18:36, 29 August 2009 (UTC)Reply

220 in base 16 has to be wrong.

edit

As commented in the text above, no sum-product number other than 0 may have a 0 in it since that would make the entire thing 0.Naraht (talk) 16:25, 28 September 2011 (UTC)Reply

I don't see a reference to 220 in base 16, but there is an example of 22O in base 36, which is correct. That number uses the digit of "O" (oh) and not the digit zero. "O" in base 36 is equivalent to 24 in base 10, so (2+2+24) * (2*2*24) = 28 * 96 = 2688 = 2*36*36 + 2*36 + 24. Steveschwei (talk) 20:08, 24 March 2016 (UTC)Reply