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A212170
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a(n) = first counting number with n distinct positive square exponents in its prime factorization.
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3
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1, 2, 48, 207360, 5643509760000, 74508333765820416000000000, 68238227014337640914957453230080000000000000000, 958098594568198616022876832154309463351366075411333120000000000000000000000000
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OFFSET
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1,2
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COMMENTS
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Next term has 122 digits.
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LINKS
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EXAMPLE
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a(2) = 48 = 2^4*3^1 has 2 distinct positive square exponents in its prime factorization (4 and 1 are both perfect squares). 48 is the smallest number with this property.
Also, 48 has 3! = 6 divisors that are not divisible by any pair of consecutive primes: 1, 2, 3, 4, 8 and 16. Cf. A166469.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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