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A086669
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a(n) = number of divisors of n that are fundamental discriminants.
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4
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1, 1, 1, 1, 2, 1, 1, 2, 1, 2, 1, 2, 2, 1, 2, 2, 2, 1, 1, 2, 2, 1, 1, 4, 2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1, 2, 4, 2, 2, 1, 2, 2, 1, 1, 4, 1, 2, 2, 2, 2, 1, 2, 4, 2, 2, 1, 4, 2, 1, 2, 2, 4, 2, 1, 2, 2, 2, 1, 4, 2, 2, 2, 2, 2, 2, 1, 4, 1, 2, 1, 4, 4, 1, 2, 4, 2, 2, 2, 2, 2, 1, 2, 4, 2, 1, 2, 2
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OFFSET
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1,5
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LINKS
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FORMULA
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EXAMPLE
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10 has divisors 1, 2, 5 and 10 of which 1 and 5 are fundamental discriminants, so a(10)=2
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PROG
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(PARI) for (n=1, 100, s=0; fordiv(i=n, i, s+=isfundamental(i)); print1(", "s))
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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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