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A003407
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Number of permutations with no 3-term arithmetic progression.
(Formerly M1201)
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3
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1, 2, 4, 10, 20, 48, 104, 282, 496, 1066, 2460, 6128, 12840, 29380, 74904, 212728, 368016, 659296, 1371056, 2937136, 6637232, 15616616, 38431556, 96547832, 198410168, 419141312, 941812088, 2181990978, 5624657008, 14765405996, 41918682488, 121728075232
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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REFERENCES
| Davis, J. A.; Entringer, R. C.; Graham, R. L.; and Simmons, G. J.; On permutations containing no long arithmetic progressions. Acta Arith. 34 (1977/78), no. 1, 81-90.
R. C. Entringer and D. E. Lackson, Problem E2440, Amer. Math. Monthly, 82 (1975), 74-77.
P. Erdos and P. Turan, On some sequences of integers, J. London Math. Soc., 11 (1936), 261-264.
LeSaulnier, Timothy D.; and Vijay, Sujith, On permutations avoiding arithmetic progressions. Discrete Math. 311 (2011), no. 2-3, 205207.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
| Bill Correll, Jr. and Randy W. Ho, Table of n, a(n) for n = 1..83
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CROSSREFS
| Sequence in context: A026666 A121880 A094536 * A151523 A026395 A090246
Adjacent sequences: A003404 A003405 A003406 * A003408 A003409 A003410
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KEYWORD
| nonn,nice
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| Sequence extended by Bill Correll, Jr., Nov 29 2011
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