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A077374
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Odd numbers whose abundance b satisfies -10 <= b <= 10, where the abundance of a number n is A(n) = sigma(n) - 2n.
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21
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1, 3, 5, 7, 9, 11, 15, 21, 315, 1155, 8925, 32445, 442365, 815634435
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Apart from {1, 3, 5, 7, 9, 11, 15, 21, 315}, subset of A088012. Probably finite. [Charles R Greathouse IV, Mar 28, 2011]
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LINKS
| Eric Weisstein's World of Mathematics, Abundance
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EXAMPLE
| sigma(32445) = 64896 and 32445*2 = 64890, which makes the odd number 32445 six away from perfection: A(32445) = 6 and hence in this sequence.
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PROG
| (PARI) forstep(n=1, 442365, 2, if(abs(sigma(n)-2*n)<=10, print1(n, ", ")))
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CROSSREFS
| Cf. A033879, A033880, A000203, A088012.
Sequence in context: A201646 A201647 A201648 * A133848 A201649 A201644
Adjacent sequences: A077371 A077372 A077373 * A077375 A077376 A077377
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KEYWORD
| nonn
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AUTHOR
| Jason Earls (zevi_35711(AT)yahoo.com), Nov 30 2002
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EXTENSIONS
| 815634435 from Farideh Firoozbakht (f.firoozbakht(AT)sci.ui.ac.ir), Jan 12 2004
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