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A063846
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Numbers n such that sigma(n) - usigma(n) > 2n
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4
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1440, 1800, 2160, 2880, 3024, 3600, 4320, 5040, 5400, 5760, 6048, 6480, 7056, 7200, 7560, 7920, 8064, 8640, 9000, 9072, 9360, 9504, 9720, 10080, 10584, 10800, 11088, 11520, 11880, 12096, 12240, 12600, 12960, 13680, 14040, 14112, 14400, 15120
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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LINKS
| Harry J. Smith, Table of n, a(n) for n=1,...,1000
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PROG
| (PARI) u(n) = sumdiv(n, d, if(gcd(d, n/d)==1, d)); j=[]; for(n=1, 20000, if(sigma(n)-u(n)>2*n, j=concat(j, n))); j
(PARI) u(n) = sumdiv(n, d, if(gcd(d, n/d)==1, d)) { n=0; for (m=1, 10^9, if(sigma(m) - u(m) > 2*m, write("b063846.txt", n++, " ", m); if (n==1000, break)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 01 2009]
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CROSSREFS
| Cf. A034448, A048146, A034683, A064597.
Sequence in context: A081426 A101998 A174277 * A179691 A078095 A157508
Adjacent sequences: A063843 A063844 A063845 * A063847 A063848 A063849
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KEYWORD
| easy,nonn
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AUTHOR
| Jason Earls (zevi_35711(AT)yahoo.com), Aug 25 2001
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