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A064143
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Sum of unitary prime divisors (A056169, A034444) of central binomial coefficient C(n,[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
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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LINKS
| Harry J. Smith, Table of n, a(n) for n=1,...,1000
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FORMULA
| a(n)=A063956[A001405(n)]
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PROG
| (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) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 09 2009]
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CROSSREFS
| A008472, A001405, A063956.
Sequence in context: A126048 A142349 A081622 * A115274 A126890 A122637
Adjacent sequences: A064140 A064141 A064142 * A064144 A064145 A064146
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KEYWORD
| nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Sep 11 2001
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