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A064143
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Sum of unitary prime divisors (A056169, A034444) of central binomial coefficient C(n, floor(n/2)).
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1
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0, 2, 3, 5, 7, 5, 12, 14, 9, 7, 23, 21, 27, 27, 29, 31, 48, 46, 62, 60, 59, 59, 81, 79, 66, 66, 59, 59, 93, 93, 124, 126, 120, 118, 125, 123, 141, 141, 158, 156, 193, 193, 225, 225, 194, 194, 243, 241, 241, 241, 245, 245, 298, 298, 321, 321, 314, 314, 365, 365, 395
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OFFSET
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1,2
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LINKS
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FORMULA
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PROG
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(PARI) { for (n=1, 1000, f=factor(binomial(n, n\2))~; a=0; for (i=1, length(f), if (f[2, i]==1, a+=f[1, i])); write("b064143.txt", n, " ", a) ) } \\ Harry J. Smith, Sep 09 2009
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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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