|
|
A131649
|
|
Number of distinct improper 2-coloring of edges for odd-order cyclic graphs.
|
|
1
|
|
|
4, 8, 16, 32, 54, 82, 116, 156, 202, 254, 312, 376, 446, 522, 604, 692, 786, 886, 992, 1104, 1222, 1346, 1476, 1612, 1754, 1902, 2056, 2216, 2382, 2554, 2732, 2916, 3106, 3302, 3504, 3712, 3926, 4146, 4372, 4604, 4842, 5086, 5336, 5592, 5854
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
3,1
|
|
LINKS
|
|
|
FORMULA
|
Conjectured g.f.: 4 + (2*x*((x-2)^2*x-4))/(x-1)^3. - Harvey P. Dale, Jul 07 2013
For n>4, a(n) = 3*n^2 - 17*n + 26 (conjectured). - Ralf Stephan, Jul 08 2013
|
|
MATHEMATICA
|
Table[If[n == 3, n + 1, If[n == 5, n + 3, 1/2 (13 - 5 n) + 3/4 (-1 + n)^2]], {n, 3, 31, 2}]
Join[{4, 8}, Table[(13-5n)/2+(3(n-1)^2)/4, {n, 7, 91, 2}]] (* Harvey P. Dale, Jul 07 2013 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
M. Razid Black (mrazidblack(AT)hotmail.com), Sep 10 2007
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|