login
A160046
Numerator of the Harary number for the cycle graph C_n.
1
0, 1, 3, 5, 15, 10, 77, 47, 75, 131, 1507, 142, 637, 353, 1089, 1487, 12937, 6989, 135451, 7255, 7381, 82451, 1925353, 84866, 430105, 1132133, 3437979, 1158863, 33980257, 1183745, 37068467, 4828073, 2436559, 41781863, 42142223, 42482563
OFFSET
1,3
COMMENTS
Extended to a(1)-a(2) using the formula.
LINKS
Eric Weisstein's World of Mathematics, Harary Index
EXAMPLE
0, 1, 3, 5, 15/2, 10, 77/6, 47/3, 75/4, 131/6, ...
MATHEMATICA
Numerator[Table[1 - Mod[n, 2] + n HarmonicNumber[Floor[(n - 1)/2]], {n, 20}]] (* Eric W. Weisstein, Dec 06 2017 *)
CROSSREFS
Cf. A160047.
Sequence in context: A277323 A340194 A353340 * A349553 A272024 A111869
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Apr 30 2009
STATUS
approved