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A071319
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First of 3 consecutive numbers which are cube-free and not squarefree, i.e. {n,n+1,n+2} are in A067259.
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0
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98, 475, 548, 603, 724, 844, 845, 1274, 1420, 1681, 1682, 1924, 2275, 2523, 2890, 3283, 3474, 3548, 3626, 3716, 4148, 4203, 4418, 4475, 4850, 4923, 4948, 5202, 5274, 5490, 5524, 5634, 5948, 6650, 6811, 6956, 7299, 7324, 7442, 7514, 7675, 8107, 8348
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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FORMULA
| A051903[n]=A051903[n+1]=A051903[n+2]=2
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EXAMPLE
| n=98=2.7.7, n=99=3.3.11, while n=100=2.2.5.5
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MATHEMATICA
| ffi[x_] := Flatten[FactorInteger[x]] lf[x_] := Length[FactorInteger[x]] ep[x_] := Table[Part[ffi[x], 2*w], {w, 1, lf[x]}] Do[s=ep[n]; s1=ep[n+1]; s2=ep[n+2]; If[Equal[Max[s], 2]&&Equal[Max[s1], 2] &&Equal[Max[s2], 2], Print[n]], {n, 1, 25000}]
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CROSSREFS
| Cf. A063528, A067259.
Sequence in context: A072607 A160828 A158129 * A203083 A202370 A184608
Adjacent sequences: A071316 A071317 A071318 * A071320 A071321 A071322
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KEYWORD
| nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), May 29 2002
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