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A131649 Number of distinct improper 2-coloring of edges for odd-order cyclic graphs. 0
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

Table of n, a(n) for n=3..47.

Index entries for sequences related to colorings

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

Sequence in context: A101434 A048168 A175341 * A003199 A189925 A007096

Adjacent sequences:  A131646 A131647 A131648 * A131650 A131651 A131652

KEYWORD

nonn

AUTHOR

M. Razid Black (mrazidblack(AT)hotmail.com), Sep 10 2007

EXTENSIONS

More terms from Harvey P. Dale, Jul 07 2013

STATUS

approved

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Last modified November 23 09:20 EST 2014. Contains 249840 sequences.