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Search: id:A061468
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| A061468 |
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d(n) + phi(n), where d(n) is the number of divisors (A000005) and phi(n) is Euler's function (A000010). |
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+0
1
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| 2, 3, 4, 5, 6, 6, 8, 8, 9, 8, 12, 10, 14, 10, 12, 13, 18, 12, 20, 14, 16, 14, 24, 16, 23, 16, 22, 18, 30, 16, 32, 22, 24, 20, 28, 21, 38, 22, 28, 24, 42, 20, 44, 26, 30, 26, 48, 26, 45, 26, 36, 30, 54, 26, 44, 32, 40, 32, 60, 28, 62, 34, 42, 39, 52, 28
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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If d(n) increases phi(n) tends to go down so the sum has a significance.
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LINKS
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T. D. Noe, Table of n, a(n) for n=1..1000
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EXAMPLE
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a(20) = d(20) + phi(20) = 6 + 8 = 14.
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MAPLE
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with(numtheory); A061468 := n-> tau(n) + phi(n);
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PROGRAM
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(PARI) { for (n=1, 1000, write("b061468.txt", n, " ", numdiv(n) + eulerphi(n)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jul 23 2009]
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CROSSREFS
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Sequence in context: A153249 A097621 A017851 this_sequence A084766 A128559 A122168
Adjacent sequences: A061465 A061466 A061467 this_sequence A061469 A061470 A061471
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KEYWORD
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nonn,easy
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), May 04 2001
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EXTENSIONS
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More terms from Winston C. Yang (winston(AT)cs.wisc.edu), May 19 2001
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