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A064143
Sum of unitary prime divisors of binomial(n, floor(n/2)).
1
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
OFFSET
1,2
LINKS
FORMULA
a(n) = A063956(A001405(n)).
PROG
(PARI) a(n) = { my(f=factor(binomial(n, n\2))); sum(i=1, #f~, if (f[i, 2]==1, f[i, 1])) } \\ Harry J. Smith, Sep 09 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Sep 11 2001
STATUS
approved