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Search: id:A080476
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| A080476 |
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Floor[ geometric mean of next n numbers]. |
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+0
2
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| 1, 2, 4, 8, 12, 18, 24, 32, 40, 50, 60, 72, 84, 98, 112, 128, 144, 162, 180, 200, 220, 242, 264, 288, 312, 338, 364, 392, 420, 450, 480, 512, 544, 578, 612, 648, 684, 722, 760, 800, 840, 882, 924, 968, 1012, 1058, 1104, 1152, 1200, 1250, 1300, 1352, 1404, 1458
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Also, floor[ harmonic mean of next n numbers].
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FORMULA
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Contribution from Yosu Yurramendi (yosu.yurramendi(AT)ehu.es), Sep 12 2008: (Start)
a(n+3)= 2*a(n+2)-a(n+1) if n even, a(n+3)= 2*a(n+2)-a(n+1)+2 if n odd, with a(1)=1, a(2)=2, a(3)=4
(End)
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EXAMPLE
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a(4) = Floor[ (7*8*9*10)^(1/4)] = 8.
a(4) = Floor[1/{ (1/7 + 1/8 + 1/9 + 1/10 )*(1/4)}] = 8.
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PROGRAM
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(PARI) a(n)=if(n<2, n>0, n^2\2)
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CROSSREFS
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Essentially the same as A007590. Cf. A000982.
Sequence in context: A152125 A100057 A007590 this_sequence A053799 A085891 A006501
Adjacent sequences: A080473 A080474 A080475 this_sequence A080477 A080478 A080479
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KEYWORD
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nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 11 2003
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EXTENSIONS
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More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 06 2003
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