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A073250
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Nonprime squarefree numbers n such that n+1 is also squarefree and nonprime, but not n-1 and n+2.
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3
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14, 21, 38, 57, 65, 69, 77, 105, 110, 114, 118, 122, 129, 133, 145, 154, 158, 165, 177, 182, 194, 205, 209, 221, 230, 237, 246, 258, 273, 290, 298, 309, 318, 326, 329, 334, 345, 354, 357, 365, 370, 381, 385, 390, 398, 402, 406, 410, 417, 426, 429, 434, 437
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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MATHEMATICA
| tQ[n_]:=!PrimeQ[n+1]&&SquareFreeQ[n+1]&&(PrimeQ[n-1]||!SquareFreeQ[n-1])&&(PrimeQ[n+2]||!SquareFreeQ[n+2])
Select[Select[Complement[Range[500], Prime[Range[PrimePi[500]]]], SquareFreeQ], tQ] (* From Harvey P. Dale, Feb 14 2011 *)
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CROSSREFS
| Cf. A000469, A005117, A073248, A073251, A073249.
Sequence in context: A100467 A094393 A128705 * A159453 A166628 A082802
Adjacent sequences: A073247 A073248 A073249 * A073251 A073252 A073253
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KEYWORD
| nonn
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AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jul 22 2002
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