complex perfect numbers
Ed Pegg Jr
edp at wolfram.com
Thu Jan 13 17:05:17 CET 2005
David Wasserman wrote:
> I couldn't find a standard definition of "perfect" in the Gaussian
integers, so I'm in favor of using any definition that 1) is somehow
related to the usual definition in N, and 2) leads to an interesting
sequence. Just make sure you specify the definition.
The "Perfect Abs" sequence could be considered
5+3i, 3+7i, 19+8i, 15+42i, 6+57i, 29+48i, 19+82i, 74+33i, 111+78i,
147+77i, 185+83i, 91+189i, 197+154i, 269+92i, 122+321i, 159+341i,
72+549i
These are numbers k where Abs[(Total[Divisors[k]] - k)] = Abs[k]
For example, the divisors for 269+92i are: 1, 2+I, 3+4i, 6+5i, 7+2i,
7+16i, 12+11i, 13+34i, 17+126i, 32+47i, 39+2i, 269+92i.
The (sum - k) is 139+248i. Abs[139+248i] == Abs[269+92i]
Perfect Abs is a weaker result than Perfect. But they have the
advantage of existing.
--Ed Pegg Jr
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