Arithmetic/Rational: Difference between revisions
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is_perfect_rational=: 2= +/@:%@,@factors</lang> |
is_perfect_rational=: 2= +/@:%@,@factors</lang> |
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Exhaustive testing would take forever: |
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<lang j> I.is_perfect_rational@"0 i.2^19 |
<lang j> I.is_perfect_rational@"0 i.2^19 |
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6 28 496 8128 |
6 28 496 8128 |
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I.is_perfect_rational@x:@"0 i.2^19x |
I.is_perfect_rational@x:@"0 i.2^19x |
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6 28 496 8128</lang> |
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More limited testing takes reasonable amounts of time: |
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<lang j> (#~ is_perfect_rational"0) (* <:@+:) 2^i.10x |
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6 28 496 8128</lang> |
6 28 496 8128</lang> |
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