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A134615
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Numbers (excluding primes and powers of primes) such that the cube mean of their prime factors is a prime (where the cube mean of c and d is ((c^3+d^3)/2)^(1/3)).
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1
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OFFSET
| 1,1
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COMMENTS
| Numbers included in A134612, but not in A025475.
a(0)=707265 is the minimal number with this property. a(2)=2284389 is the greatest such number <10^7.
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EXAMPLE
| a(0)=707265, since 707265=3*3*3*5*13*13*31 and ((3*3^3+5^3+2*13^3+31^3)/7)^(1/3)=4913^(1/3)=17.
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CROSSREFS
| Cf. A001597, A025475, A134333, A134344, A134376.
Cf. A134600, A134602, A134605, A134608, A134613, A134617, A134619, A134621.
Sequence in context: A183835 A203834 A140943 * A186607 A083613 A083614
Adjacent sequences: A134612 A134613 A134614 * A134616 A134617 A134618
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KEYWORD
| nonn,bref
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AUTHOR
| Hieronymus Fischer (Hieronymus.Fischer(AT)gmx.de), Nov 11 2007
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