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A072842 Largest m such that we can partition the set {1,2,...,m} into n subsets with the property that we never have a+b=c for any distinct elements a, b, c in one subset. +0
1
2, 8, 23, 66, 196 (list; graph; listen)
OFFSET

1,1

COMMENT

The fourth term is at least 66 (Ernst Munter), from { 24 26 27 28 29 30 31 32 33 36 37 38 39 41 42 44 45 46 47 48 49 } { 9 10 12 13 14 15 17 18 20 54 55 56 57 58 59 60 61 62 } { 1 2 4 8 11 16 22 25 40 43 53 66 } { 3 5 6 7 19 21 23 34 35 50 51 52 63 64 65 }

REFERENCES

EFNet #math, Jul 23 2002 (can we replace this with a link? - njas)

P. Bornsztein, An extension of a theorem of Schur, Acta Arithmetica, 101.4 (2001), pp. 395-399.

G. W. Walker, Solution to the problem E985, American Mathematical Monthly, Vol. 59 (1952), p. 253.

LINKS

Dr. Dobb's Journal, Solutions to the "Monopoles" Problem

FORMULA

It is known that 315^((n-1)/5) =< a(n) =< [n*e*(n!)] where [ ] denotes the integer part. - Pierre Bornsztein (bornsztein(AT)voila.fr), Sep 02 2003

EXAMPLE

a(2) = 8 because we may partition the set into {1, 2, 4, 8} and {3, 5, 6, 7} but in no other ways; attempting to add 9 to either will produce a set with the property that a+b=c for some a,b,c (1+8=9 or 2+7=9)

CROSSREFS

The requirement that a not equal b is the only difference between these numbers and the Schur numbers A045652.

Sequence in context: A014285 A079460 A018042 this_sequence A138387 A007346 A084744

Adjacent sequences: A072839 A072840 A072841 this_sequence A072843 A072844 A072845

KEYWORD

nonn,more,nice

AUTHOR

Tor G. J. Myklebust (pi(AT)flyingteapot.bnr.usu.edu), Jul 24 2002

EXTENSIONS

Additional comments from Rob Pratt and Brendan McKay, Nov 02 2002

More terms from Pierre Bornsztein (bornsztein(AT)voila.fr), Sep 02 2003

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Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.


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