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Search: id:A119901
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| A119901 |
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Difference between two consecutive squares enclosing 3^(2n+1). |
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+0
1
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| 3, 11, 31, 93, 281, 841, 2525, 7575, 22727, 68183, 204551, 613655, 1840965, 5522897, 16568691, 49706071, 149118215, 447354647, 1342063941, 4026191825, 12078575475, 36235726425, 108707179277, 326121537829, 978364613487
(list; graph; listen)
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OFFSET
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0,1
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FORMULA
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a(n) = 2*Floor(3^((2n + 1)/2)) + 1.
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EXAMPLE
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a(2)=31 because 3^(2*2+1)=3^5=243, 15^2<243<16^2, and 16^2-15^2=256-225=31
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MATHEMATICA
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f[n_] := 2*Floor[3^((2n + 1)/2)] + 1; Table[f[n], {n, 0, 25}] (*Chandler*)
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CROSSREFS
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Sequence in context: A034543 A054343 A108898 this_sequence A106934 A095692 A076477
Adjacent sequences: A119898 A119899 A119900 this_sequence A119902 A119903 A119904
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KEYWORD
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nonn
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AUTHOR
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Zak Seidov (zakseidov(AT)yahoo.com), May 27 2006
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EXTENSIONS
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Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Jun 09 2006
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