Talk:Perfect digit-to-digit invariant

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Untitled[edit]

00 is undefined, as it refers to a number (0) divided by zero; at any rate, 00 wouldn't be equal to 0, since all numbers raised to 0 are 1. Where do we get our convention? —Preceding unsigned comment added by 161.130.140.73 (talkcontribs)

Yes, in general, 00 is undefined. However, the convention that 00 is taken to be 0 when calculating PDDI's is the one used in OEIS, which presumably in turn takes that convention from the sources that it references. Gandalf61 (talk) 10:04, 4 November 2010 (UTC)[reply]
Wrong. In the original article from Daan van Berkel, the URL [1] is referenced. It uses the "convention" (which is not really a convention, but let's not go into that) 0^0=1. —Preceding unsigned comment added by 161.53.230.212 (talk) 05:27, 7 March 2011 (UTC)[reply]


I don’t think you need this convention for 0. You just need to consider that 0 has 0 digits, and that a sum of 0 elements is 0. Both conventions are sensible, and usually used. Lango (talk) 06:29, 5 August 2014 (UTC)[reply]

Merge proposal[edit]

  • Support They clearly describe the same thing, and which article redirects to which makes absolutely no difference to me. --Slashme (talk) 15:53, 8 September 2015 (UTC)[reply]

why not say a<=b+1 ?[edit]

it seems simpler than just saying there is "some number a >= k ..." 72.35.104.10 (talk) 16:33, 22 September 2016 (UTC)[reply]

Definition of Tetration[edit]

We have this line:

The process of raising a number to the power of itself is known as tetration.

This appears not to be the same thing at all. Can someone more expert in mathematics than me check this over? I may be missing something. --Matt Westwood 22:14, 26 August 2017 (UTC)[reply]

"Denary"?[edit]

I gather this is intended to be a name for base ten that is more consistent with binary, ternary etc? It's nonstandard and probably confusing to readers. Shouldn't this article at least define it, or better yet just use "decimal" like every other Wikipedia article? Patallurgist (talk) 23:38, 30 April 2018 (UTC)[reply]

0^0 is not 0[edit]

0 doesn't do it. — Preceding unsigned comment added by Gil Costa (talkcontribs) 22:27, 6 March 2019 (UTC)[reply]

There's no such thing[edit]

the convention that — Preceding unsigned comment added by Gil Costa (talkcontribs) 22:37, 6 March 2019 (UTC)[reply]

Something's wrong with the headings[edit]

So apparently putting math code in the heading kinda breaks the table of contents:

1 Definition

2 Perfect digit-to-digit invariants and cycles of ?'"`UNIQ--postMath-0000002C-QINU`"'? for specific ?'"`UNIQ--postMath-0000002D-QINU`"'?

2.1 Convention ?'"`UNIQ--postMath-0000002F-QINU`"'?

2.2 Convention ?'"`UNIQ--postMath-00000033-QINU`"'?

3 Programming examples

3.1 Python

3.1.1 Convention ?'"`UNIQ--postMath-0000003C-QINU`"'?

3.1.2 Convention ?'"`UNIQ--postMath-0000003D-QINU`"'?

What should I do? Go to the table of contents template talk? Wilh3lmGo here to trout me if I do a stupid 22:26, 8 December 2021 (UTC) Update: The TOC is generated automatically so I don't know what to do... Wilh3lmGo here to trout me if I do a stupid 22:29, 8 December 2021 (UTC)[reply]

I'm not sure if there's a new bug in the TOC generation (I'm pretty sure this wasn't happening the last time I looked at this article), but MOS:HEAD says that section headings should not contain <math> markup, so I think a reasonable solution is to rewrite the headings without math tags. CodeTalker (talk) 22:37, 8 December 2021 (UTC)[reply]