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0, 0, 0, 0, 0, 2, 0, 3, 2, 4, 0, 11, 0, 6, 8, 11, 0, 18, 0, 21, 12, 10, 0, 40, 8, 12, 16, 31, 0, 52, 0, 36, 20, 16, 24, 75, 0, 18, 24, 74, 0, 76, 0, 51, 60, 22, 0, 121, 18, 60, 32, 61, 0, 100, 40, 108, 36, 28, 0, 198, 0, 30, 88, 100, 48, 124, 0, 81, 44, 140, 0, 243, 0, 36, 104
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,6
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COMMENTS
| a(n) = 0 if n is prime, otherwise >=0; first part of formula provides estimation of sigma(n).
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LINKS
| Harry J. Smith, Table of n, a(n) for n=1,...,1000
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EXAMPLE
| n = 4: tau(4) = 3, (3*(4+1)/2)-7 = 0.5 so a(4) = 0; n = 12: tau(12) = 6, (6*(12+1)/2)-28 = 39-28 = 11 = a(12).
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PROG
| (PARI) { for (n=1, 1000, a = numdiv(n)*(n + 1)\2 - sigma(n); write("b063749.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Aug 29 2009]
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CROSSREFS
| A000005, A000203.
Sequence in context: A140944 A057860 A092915 * A008807 A008819 A169646
Adjacent sequences: A063746 A063747 A063748 * A063750 A063751 A063752
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KEYWORD
| nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Aug 14 2001
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