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Search: id:A064460
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| A064460 |
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Number of distinct non-squarefree entries in n-th row of Pascal's triangle. |
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+0
3
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| 0, 0, 0, 0, 1, 0, 1, 0, 3, 4, 3, 0, 5, 2, 2, 1, 8, 6, 9, 6, 7, 6, 6, 0, 11, 11, 10, 13, 13, 9, 13, 10, 16, 15, 14, 14, 18, 15, 13, 14, 19, 15, 15, 9, 15, 19, 14, 3, 24, 24, 25, 24, 24, 18, 26, 25, 28, 26, 25, 19, 27, 18, 12, 28, 32, 31, 31, 30, 31, 27, 30, 27, 36, 33, 29, 36, 36, 32
(list; graph; listen)
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OFFSET
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0,9
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EXAMPLE
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a(13) = 2 because C(13,5) = 3^2*11*13 and C(13,6) = 2^2*3*11*13.
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MATHEMATICA
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f[ n_ ] := (c = 0; k = 1; While[ k < n/2 + .5, If[ Union[ Transpose[ FactorInteger[ Binomial[ n, k ] ] ] [ [ 2 ] ] ] [ [ -1 ] ] > 1, c++ ]; k++ ]; c); Table[ f[ n ], {n, 0, 100} ]
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CROSSREFS
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Cf. A064461, A064462.
Adjacent sequences: A064457 A064458 A064459 this_sequence A064461 A064462 A064463
Sequence in context: A072565 A059114 A072681 this_sequence A108481 A078070 A111028
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KEYWORD
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easy,nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), Oct 02 2001
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