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Search: id:A133447
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| A133447 |
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Nonsemiprime hyperperfect numbers. |
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+0
1
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| 325, 2133, 10693, 16513, 19521, 51301, 159841, 176661, 214273, 306181, 1433701, 1570153, 1950625, 2469601, 2924101, 5199013, 9398593, 10445221, 15407173, 23548753, 28600321, 39147301, 60110701, 62722153, 88347781, 112803841
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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The other 25 of the first 35 values of A007592 are all semiprimes A001358.
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FORMULA
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A100959 INTERSECTION A007592.
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EXAMPLE
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a(1) = 325 = 5^2 * 13.
a(2) = 2133 = 3^3 * 79.
a(3) = 10693 = 17^2 * 37.
a(4) = 16513 = 7^2 * 337.
a(5) = 19521 = 3^4 * 341.
a(6) = 51301 = 29^2 * 61.
a(7) = 159841 = 11^2 * 1321.
a(8) = 176661 = 3^5 * 727.
a(9) = 214273 = 47^2 * 97.
a(10) = 306181 = 53^2 * 109.
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MAPLE
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a034897 := [] : fd := fopen("b034897.txt", READ) : bf := fscanf(fd, "%d %d") : while nops(bf) <> 0 do a034897 := [op(a034897), op(2, bf) ] ; bf := fscanf(fd, "%d %d") ; od: a007592 := [] : for n in a034897 do m := (n-1)/( numtheory[sigma](n)-n-1) ; if m > 1 then a007592 := [op(a007592), n] ; fi ; od: isA100959 := proc(n) if numtheory[bigomega](n) <> 2 then true ; else false ; end: end: for n in a007592 do if isA100959(n) then printf("%d, ", n) ; fi ; od: - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 08 2008
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CROSSREFS
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Cf. A001358, A007592, A100959.
Sequence in context: A025286 A025304 A031714 this_sequence A031606 A121000 A048909
Adjacent sequences: A133444 A133445 A133446 this_sequence A133448 A133449 A133450
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KEYWORD
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nonn
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AUTHOR
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Jonathan Vos Post (jvospost2(AT)yahoo.com), Dec 22 2007
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EXTENSIONS
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More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 08 2008
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