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A059442 Array of Ramsey numbers R(n,k) read by antidiagonals. 3
2, 3, 3, 4, 6, 4, 5, 9, 9, 5, 6, 14, 18, 14, 6, 7, 18, 25, 25, 18, 7, 8, 23 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,1

REFERENCES

L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 288.

H. J. Ryser, Combinatorial Mathematics, Chapter 4 - A Theorem of Ramsey, Mathematical Association of America, Carus Mathematical Monograph 14, 1963, p. 42.

LINKS

Table of n, a(n) for n=0..22.

J. G. Kalbfleisch, Construction of special edge-chromatic graphs, Canad. Math. Bull., 8 (1965), 575-584.

Stanislaw Radziszowski, Small Ramsey Numbers, The Electronic Journal of Combinatorics, Dynamic Surveys, DS1, Mar 3 2017.

Eric Weisstein's World of Mathematics, Ramsey Number

Wikipedia, Ramsey's theorem

Jin Xu and C. K. Wong, Self-complementary graphs and Ramsey numbers I, Discrete Math., 223 (2000), 309-326.

EXAMPLE

Array R(n,k), n >= 2, k >= 2, begins:

   2,  3,  4,  5,  6,  7,  8,  9, 10,

   3,  6,  9, 14, 18, 23, 28, 36,

   4,  9, 18, 25,  ?,  ?,  ?,

   5, 14, 25,  ?,  ?,  ?,

   6, 18,  ?,  ?,  ?,

   7, 23,  ?,  ?,

   8, 28,  ?,

   9, 36,

  10,

CROSSREFS

Second row gives A000791.

Sequence in context: A031501 A279417 A203996 * A225273 A014410 A180986

Adjacent sequences:  A059439 A059440 A059441 * A059443 A059444 A059445

KEYWORD

nonn,tabl,nice,hard

AUTHOR

N. J. A. Sloane, Feb 01 2001

EXTENSIONS

Next entry is in range 35-41.

More terms in example section (antidiagonals 6-10. Cf. A000791) from Omar E. Pol, Jun 11 2012

STATUS

approved

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Last modified August 14 17:54 EDT 2022. Contains 356122 sequences. (Running on oeis4.)