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Search: id:A059842
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| A059842 |
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The next square after a(n)^3 is a(n+1)^2. |
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+0
2
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| 1, 2, 3, 6, 15, 59, 454, 9674, 951501, 928140821, 28276184777782, 150359618976700758746, 1843727887745124274995859697327, 2503486403859294888221025578988349446337176495
(list; graph; listen)
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OFFSET
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1,2
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LINKS
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Harry J. Smith, Table of n, a(n) for n=1,...,21
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FORMULA
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a(n+1) = min { i | i^2 > a(n)^3 }
a(n+1) = Floor( Sqrt ( a(n)^3 )) + 1 - Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 22 2001
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EXAMPLE
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a(4)=6 has cube 216. The next square is 225=15^2. So a(5)=15.
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MAPLE
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a := proc(n) option remember: if n=1 then RETURN(1) fi: if n=2 then RETURN(2) fi: ceil(a(n-1)^((3.)/(3-1))): end: Digits := 200: for n from 1 to 20 do printf(`%a, `, a(n)) od:
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MATHEMATICA
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f[n_Integer] := Floor[ N[ Sqrt[n^3] ] ] + 1; NestList[f, 1, 15]
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PROGRAM
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(PARI) { a=0; for (n=1, 21, write("b059842.txt", n, " ", a=floor(sqrt(a^3)) + 1); ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jun 29 2009]
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CROSSREFS
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Sequence in context: A082094 A060796 A061059 this_sequence A001529 A069354 A007364
Adjacent sequences: A059839 A059840 A059841 this_sequence A059843 A059844 A059845
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KEYWORD
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nonn
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AUTHOR
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Rainer Rosenthal (r.rosenthal(AT)web.de), Feb 26 2001
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EXTENSIONS
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More terms from James A. Sellers (sellersj(AT)math.psu.edu), Mar 15 2001
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