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A020661 lexicographically earliest increasing sequence of nonnegative numbers that contains no arithmetic progression of length 9. 28
0, 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, 16, 18, 19, 20, 21, 22, 23, 26, 27, 28, 29, 30, 31, 32, 33, 36, 37, 38, 39, 40, 42, 43, 44, 45, 46, 47, 48, 49, 52, 54, 55, 56, 57, 58, 59, 63, 64, 65, 66, 67, 68, 69, 70, 77, 78, 79, 80, 81, 82, 83, 84, 86, 87, 90, 91, 93, 94, 95, 96, 97 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

David W. Wilson, Table of n, a(n) for n = 1..10000

CROSSREFS

Summary of increasing sequences avoiding arithmetic progressions of specified lengths (the second of each pair is obtained by adding 1 to the first):

3-term AP: A005836 (>=0), A003278 (>0);

4-term AP: A005839 (>=0), A005837 (>0);

5-term AP: A020654 (>=0), A020655 (>0);

6-term AP: A020656 (>=0), A005838 (>0);

7-term AP: A020657 (>=0), A020658 (>0);

8-term AP: A020659 (>=0), A020660 (>0);

9-term AP: A020661 (>=0), A020662 (>0);

10-term AP: A020663 (>=0), A020664 (>0).

Sequence in context: A277050 A013937 A118065 * A284837 A068937 A285316

Adjacent sequences:  A020658 A020659 A020660 * A020662 A020663 A020664

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified December 13 19:20 EST 2017. Contains 295976 sequences.