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Search: id:A048279
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| A048279 |
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Values of n for which no values of C[ n,k ] except k=0 and k=n are square-free. |
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+0
2
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| 0, 1, 9, 16, 18, 27, 32, 36, 48, 49, 50, 56, 64, 72, 80, 81, 96, 98, 99, 100, 108, 112, 121, 126, 128, 135, 136, 144, 147, 148, 153, 162, 169, 171, 175, 176, 180, 192, 196, 198, 200, 216, 225, 243, 244, 245, 248, 250, 252, 256, 264, 272, 276, 288, 289, 294, 300
(list; graph; listen)
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OFFSET
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0,3
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EXAMPLE
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n=9, C[ n,k ]=(1),9,36,84,126,126,84,36,9,(1); all values include squares.
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MATHEMATICA
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f[n_] := (c = 0; k = 1; While[k < n, If[ Union[ Transpose[ FactorInteger[ Binomial[n, k]]] [[2]]] [[ -1]] > 1, c++ ]; k++ ]; c); Select[Range[150], f[ # ] == # - 1 &]
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CROSSREFS
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Cf. A048276-A048279.
Adjacent sequences: A048276 A048277 A048278 this_sequence A048280 A048281 A048282
Sequence in context: A131746 A092095 A034040 this_sequence A072836 A068824 A095961
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu)
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Oct 02 2001
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