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Search: id:A101550
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| A101550 |
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Lopsided (or biased) numbers: numbers n such that the largest prime factor of n is > 2*sqrt(n). |
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+0
2
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| 5, 7, 11, 13, 17, 19, 22, 23, 26, 29, 31, 34, 37, 38, 39, 41, 43, 46, 47, 51, 53, 57, 58, 59, 61, 62, 67, 68, 69, 71, 73, 74, 76, 79, 82, 83, 86, 87, 89, 92, 93, 94, 97, 101, 103, 106, 107, 109, 111, 113, 115, 116, 118, 122, 123, 124, 127, 129, 131, 134, 137, 139, 141
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Note that all primes > 3 are here. See A101549 for composite lopsided numbers.
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REFERENCES
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G. Everest et al., Primes generated by recurrence sequences, Amer. Math. Monthly, 114 (No. 5, 2007), 417-431.
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LINKS
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T. D. Noe, Table of n, a(n) for n = 1..1000
G. Everest, S. Stevens, D. Tamsett, and T. Ward, Primitive Divisors of Quadratic Polynomial Sequences
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MAPLE
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with(numtheory): a:=proc(n) if max((seq(factorset(n)[j], j=1..nops(factorset(n)))))^2>4*n then n else fi end: seq(a(n), n=2..170); - Emeric Deutsch (deutsch(AT)duke.poly.edu), May 27 2007
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MATHEMATICA
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Select[Range[2, 200], FactorInteger[ # ][[ -1, 1]]>2Sqrt[ # ]&]
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CROSSREFS
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Cf. A063763 (composite n such that the largest prime factor > sqrt(n)), A064052 (n such that the largest prime factor > sqrt(n)).
Sequence in context: A035035 A113909 A111906 this_sequence A136801 A106571 A067291
Adjacent sequences: A101547 A101548 A101549 this_sequence A101551 A101552 A101553
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KEYWORD
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nonn,new
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AUTHOR
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T. D. Noe (noe(AT)sspectra.com), Dec 06 2004
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EXTENSIONS
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Edited by njas, Jul 02 2008 at the suggestion of R. J. Mathar
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