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A320757
For p the n-th prime congruent to 1 (mod 4), a(n) is the clique number of the quadratic residue (Paley) graph over F_p, the field of order p.
1
2, 3, 3, 4, 4, 5, 5, 5, 5, 5, 6, 5, 6, 7, 7, 7, 7, 8, 7, 7, 8, 9, 7, 7, 7, 8, 8, 7, 8, 8, 9, 9, 9, 9, 8, 9, 9, 9, 9, 9, 11, 9, 11, 11, 9, 9, 11, 11, 9, 10, 11, 11, 12, 11, 11, 11, 11, 11, 11, 10, 10, 11
OFFSET
1,1
LINKS
Eric Weisstein's World of Mathematics, Clique Number
Eric Weisstein's World of Mathematics, Paley Graph
EXAMPLE
a(1) = 2, since the Paley graph of order 5 is a 5-cycle, and contains no triangle.
CROSSREFS
Cf. A002144 (primes of form 4n + 1), A320837.
Sequence in context: A336515 A130500 A072073 * A061716 A362692 A341053
KEYWORD
nonn,more
AUTHOR
Jeremy F. Alm, Oct 20 2018
STATUS
approved