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A064139
Sum of divisors of central binomial coefficient binomial(n, floor(n/2)).
1
1, 3, 4, 12, 18, 42, 48, 144, 312, 728, 1152, 2688, 4704, 10080, 13104, 39312, 54432, 127008, 181440, 423360, 1128960, 2419200, 2903040, 6773760, 14999040, 32140800, 74995200, 160704000, 303264000, 626745600, 646963200, 1940889600
OFFSET
1,2
LINKS
FORMULA
a(n) = A000203(A001405(n)).
MATHEMATICA
a[n_] := DivisorSigma[1, Binomial[n, Floor[n/2]]]; Array[a, 32] (* Amiram Eldar, Apr 01 2024 *)
PROG
(PARI) a(n) = sigma(binomial(n, n\2)); \\ Harry J. Smith, Sep 08 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Sep 11 2001
EXTENSIONS
Offset changed from 0 to 1 by Harry J. Smith, Sep 08 2009
STATUS
approved