Revision History for A111227
(Underlined text is an addition;
strikethrough text is a deletion.)
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#5 by Reinhard Zumkeller at Fri Aug 03 04:48:46 EDT 2012
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#4 by Reinhard Zumkeller at Thu Aug 02 20:04:12 EDT 2012
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| PROG
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(Haskell)
a111227 n = a111227_list !! (n-1)
a111227_list = filter (\x -> a019294 x > x) [1..]
-- Reinhard Zumkeller, Aug 02 2012
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approved
editing
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#3 by R. J. Mathar at Fri Oct 07 14:22:31 EDT 2011
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#2 by R. J. Mathar at Fri Oct 07 14:22:21 EDT 2011
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| REFERENCES
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Graeme L. Cohen and Herman J. J. te Riele, Iterating the sum-of-divisors function, Experimental Mathematics, 5 (1996), pp. 94.
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| LINKS
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<Graeme L. Cohen and Herman J. J. te Riele, <a href="http://www.expmathemis.orgde/journals/EM/expmath/volumes/5/5.html">Iterating the sum-of-divisors function</a> Experimental Mathematics, 5 (1996)</a>), p 94.
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approved
editing
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#1 by N. J. A. Sloane at Tue Jan 24 03:00:00 EST 2006
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| NAME
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Numbers n where A019294(n) > n.
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| DATA
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3, 11, 29, 53, 58, 59, 67, 101, 109, 131, 149, 173, 202, 239, 461, 479, 659, 1031, 1319, 1579, 1847
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| OFFSET
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1,1
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| COMMENTS
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A number n is called (m,k)-perfect if sigma^m(n) = k*n. A019294(n) gives minimal values of m for n. a(n) are the values where A019294(n) > n.
Corresponding values of m and k are in A111726, A111727.
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| REFERENCES
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Graeme L. Cohen and Herman J. J. te Riele, Iterating the sum-of-divisors function, Experimental Mathematics, 5 (1996), pp. 94.
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| LINKS
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<a href="http://www.expmath.org/expmath/volumes/5/5.html">Experimental Mathematics, 5 (1996)</a>
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| KEYWORD
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hard,nonn
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| AUTHOR
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Lambert Klasen (lambert.klasen(AT)gmx.net), Oct 26 2005
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| STATUS
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approved
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