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Given positive integers k_1, k_2, there is an
integer m such that given any partition {1,2, ..., m}=P_1 U P_2, there is
an arithmetic progression of length k_1 in P_1 or k_2 consecutive integers in P_2.
Let us denote the least
m with this property by w_1(2; k_1, k_2). Some previously unknown van der Waerden type numbers (bold) are computed (Aug. 2008), by Tanbir Ahmed (ta_ahmed at cs dot concordia dot ca) using the wonderful machines at ConCoCO Research Laboratory van der Waerden type numbers known so far: |
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| w_1(2; k_1, k_2) | = | Reference |
| w_1(2; 3, 2) | = 9 | Brown, Landman, Robertson [1] |
| w_1(2; 3, 3) | = 23 | Brown, Landman, Robertson [1] |
| w_1(2; 3, 4) | = 34 | Brown, Landman, Robertson [1] |
| w_1(2; 3, 5) | = 73 | Brown, Landman, Robertson [1] |
| w_1(2; 3, 6) | = 113 | Brown, Landman, Robertson [1] |
| w_1(2; 3, 7) | = 193 | Brown, Landman, Robertson [1] |
| w_1(2; 3, 8) | = 238 | * |
| w_1(2; 4, 2) | = 18 | * |
| w_1(2; 4, 3) | = 62 | * |
| w_1(2; 4, 4) | = 229 | * |
| w_1(2; 5, 2) | = 32 | * |
| w_1(2; 6, 2) | = 60 | * |
| w_1(2; 7, 2) | = 301 | * |
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[1] Brown T., Landman B., Robertson A., Bounds on some van der Waerden numbers, Journal
of Combinatorial Theory, Series A Volume 115, Issue 7 (2008) 1304-1309 Known van der Waerden numbers. |
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