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%I #7 Dec 07 2017 22:13:59
%S 0,1,3,5,15,10,77,47,75,131,1507,142,637,353,1089,1487,12937,6989,
%T 135451,7255,7381,82451,1925353,84866,430105,1132133,3437979,1158863,
%U 33980257,1183745,37068467,4828073,2436559,41781863,42142223,42482563
%N Numerator of the Harary number for the cycle graph C_n.
%C Extended to a(1)-a(2) using the formula.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/HararyIndex.html">Harary Index</a>
%e 0, 1, 3, 5, 15/2, 10, 77/6, 47/3, 75/4, 131/6, ...
%t Numerator[Table[1 - Mod[n, 2] + n HarmonicNumber[Floor[(n - 1)/2]], {n, 20}]] (* _Eric W. Weisstein_, Dec 06 2017 *)
%Y Cf. A160047.
%K nonn
%O 1,3
%A _Eric W. Weisstein_, Apr 30 2009
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