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A028236
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If n = Product (p_j^k_j), a(n) = numerator of Sum 1/p_j^k_j.
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4
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1, 1, 1, 1, 1, 5, 1, 1, 1, 7, 1, 7, 1, 9, 8, 1, 1, 11, 1, 9, 10, 13, 1, 11, 1, 15, 1, 11, 1, 31, 1, 1, 14, 19, 12, 13, 1, 21, 16, 13, 1, 41, 1, 15, 14, 25, 1, 19, 1, 27, 20, 17, 1, 29, 16, 15, 22, 31, 1, 47, 1, 33, 16, 1, 18, 61, 1, 21, 26, 59, 1, 17, 1, 39, 28, 23, 18, 71, 1, 21, 1, 43
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,6
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LINKS
| K. Brockhaus, Table of n, a(n) for n = 1..10000 [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Nov 06 2010]
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FORMULA
| Fraction is additive with a(p^e) = 1/p^e.
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PROG
| (MAGMA) a028236:=func< k | k eq 1 select 1 else Numerator(&+[ f[i, 1]^-f[i, 2]: i in [1..#f] ]) where f is Factorization(k) >; [ a028236(n):n in [1..82] ]; [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Nov 06 2010]
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CROSSREFS
| Denominator is n (A000027).
Sequence in context: A035316 A068316 A028235 * A066504 A168677 A140210
Adjacent sequences: A028233 A028234 A028235 * A028237 A028238 A028239
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KEYWORD
| nonn,easy,frac
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| More terms from Erich Friedman (erich.friedman(AT)stetson.edu).
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