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A217004 Numbers arising in computing the Turan function of cycles of length 4. 0
273, 307, 381, 553, 651, 757, 871, 993, 1057, 1407, 1723, 1893, 2257, 2451, 2863, 3541, 3783, 4161, 4557, 5113, 5403, 6321, 6643, 6973, 8011, 9507, 10303, 10713, 11557, 11991, 12883, 14763, 15751, 16257, 16513, 17293, 18907, 19461, 22351, 22953, 24807, 26733, 28057, 28731, 30103 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Z. Füredi, Graphs without quadrilaterals, J. Combin. Theory (A) 34 (1983), 187-190.
Z. Füredi, On the number of edges of quadrilateral-free graphs, J. Combin. Theory (B) 68 (1996), 1-6.
Oleg Pikhurko, A Note on the Turan Function of Even Cycles, Proc Amer Math Soc, 140 (2012) 3687-3992.
FORMULA
a(n) = q^2+q+1 where q=A000961(n+10). - R. J. Mathar, Jul 12 2013
CROSSREFS
Sequence in context: A043804 A043812 A043821 * A256638 A338557 A347882
KEYWORD
nonn,easy
AUTHOR
Jonathan Vos Post, Sep 22 2012
STATUS
approved

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Last modified February 29 06:19 EST 2024. Contains 370402 sequences. (Running on oeis4.)