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A037092
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Number of triples {i,j,k}, i>1, j>1, k>1, such that ijk < n^3.
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2
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0, 7, 35, 104, 238, 482, 851, 1402, 2147, 3179, 4497, 6210, 8324, 10921, 14048, 17759, 22146, 27247, 33158, 39953, 47652, 56372, 66135, 77187, 89351, 102902, 117801, 134252, 152148, 171853, 193328, 216471, 241557, 268780, 298017, 329515
(list; graph; refs; listen; history; internal format)
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OFFSET
| 2,2
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FORMULA
| sum(sum(floor((n^3-1)/(ij))-j+1, j=i..floor(sqrt((n^3-1)/i))), i=2..n-1)
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EXAMPLE
| f(3)=7 because the only triples ijk < 27 are (2,2,2) (2,2,3) (2,2,4) (2,2,5) (2,2,6) (2,3,3) (2,3,4)
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CROSSREFS
| Cf. A037048.
Sequence in context: A152744 A169607 A130884 * A015667 A206723 A124090
Adjacent sequences: A037089 A037090 A037091 * A037093 A037094 A037095
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KEYWORD
| nonn
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AUTHOR
| Joe K. Crump (joecr(AT)carolina.rr.com)
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