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A117582
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For successive primes p, the number of ratios of the form n^2/(n^2-1) which factor into primes less than or equal to p.
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2
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0, 2, 5, 10, 15, 24, 34, 46, 57, 74, 90, 114, 141
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| By a theorem of Stormer, the number of ratios m/(m-1) factoring into primes only up to p is finite. A proportion of these have square denominators.
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REFERENCES
| E. F. Ecklund and R. B. Eggleton, Prime factors of consecutive integers, Amer. Math. Monthly, 79 (1972), 1082-1089.
D. H. Lehmer, On a problem of Stormer, Ill. J. Math., 8 (1964), 57-69.
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CROSSREFS
| Cf. A002071, A117583.
Sequence in context: A013927 A163059 A099738 * A002134 A062472 A086849
Adjacent sequences: A117579 A117580 A117581 * A117583 A117584 A117585
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KEYWORD
| hard,nonn
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AUTHOR
| Gene Ward Smith (genewardsmith(AT)gmail.com), Apr 02 2006
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