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A064146 Sum of non-unitary prime divisors (A034444, A056169) of central binomial coefficient C(n,[n/2]) (A001405). If A001405(n) is squarefree (A046098) then a(n)=0. 1
0, 0, 0, 0, 0, 2, 0, 0, 3, 5, 0, 2, 2, 2, 3, 3, 0, 2, 0, 2, 2, 2, 0, 2, 7, 7, 10, 10, 5, 5, 3, 3, 3, 5, 5, 7, 7, 7, 3, 5, 2, 2, 2, 2, 10, 10, 8, 10, 12, 12, 12, 12, 9, 9, 2, 2, 2, 2, 2, 2, 2, 2, 10, 10, 7, 9, 7, 9, 5, 5, 0, 2, 2, 2, 7, 7, 14, 14, 7, 9, 12, 12, 5, 5, 10, 10, 10, 10, 5, 5, 12, 12, 12 (list; graph; refs; listen; history; internal format)
OFFSET

1,6

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,1000

FORMULA

a(n)=A063958[A001405(n)]

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("b064146.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 09 2009]

CROSSREFS

A008472, A001405, A063958, A034444, A056169, A046098, A048243.

Sequence in context: A188430 A013585 A053653 * A028590 A074644 A130123

Adjacent sequences:  A064143 A064144 A064145 * A064147 A064148 A064149

KEYWORD

nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), Sep 11 2001

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Last modified February 15 08:49 EST 2012. Contains 205740 sequences.