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A064893
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Smallest number with "binary potency" of n. Blocks of at least n 0's must be inserted between the bits of a(n) to "dilute" it into a nonprime.
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2
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OFFSET
| 0,2
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COMMENTS
| Are there values for all a(n)? Is the sequence monotonic?
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EXAMPLE
| 1 is nonprime (potency 0) so a(0) = 1; 2 = 10 -> 0100 = 4, potency 1, so a(1) = 2; 3 = 11 -> 0101 = 5 -> 001001 = 9, potency 2 so a(2) = 3; potency 4 first appears for 29, so a(4) = 29; etc
4088027 dilutes into 5858670956869, 10540679875665334793, 20632314388123853242044433, 41873360515671700575496732442657 and 86420918502629375433474712237244678209, all prime. But the next dilution, 179810732934100666625066494484898891551473793, is composite.
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CROSSREFS
| Cf. A000040, A064891, A064892.
Sequence in context: A053998 A144953 A132282 * A141514 A078727 A076977
Adjacent sequences: A064890 A064891 A064892 * A064894 A064895 A064896
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KEYWORD
| base,nonn,nice
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AUTHOR
| Marc LeBrun (mlb(AT)well.com), Oct 10 2001
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EXTENSIONS
| a(6) from Don Reble djr(AT)nk.ca and Fred W. Helenius fredh(AT)ix.netcom.com, Oct 11, 2001. a(7) from Hans Havermann (gladhobo(AT)teksavvy.com), Oct 13, 2001
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