|
%I #10 Jun 22 2018 04:39:23
%S 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,
%T 66,59,59,93,93,124,126,120,118,125,123,141,141,158,156,193,193,225,
%U 225,194,194,243,241,241,241,245,245,298,298,321,321,314,314,365,365,395
%N Sum of unitary prime divisors (A056169, A034444) of central binomial coefficient C(n, floor(n/2)).
%H Harry J. Smith, <a href="/A064143/b064143.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) = A063956(A001405(n)).
%o (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
%Y Cf. A008472, A001405, A063956.
%K nonn
%O 1,2
%A _Labos Elemer_, Sep 11 2001
|
