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A143786 Number of arithmetic progressions from m to n; a rectangular array, m>=0, n>=0, by antidiagonals. 0
1, 1, 1, 2, 1, 2, 2, 1, 1, 2, 3, 2, 1, 2, 3, 2, 2, 1, 1, 2, 2, 4, 3, 2, 1, 2, 3, 4, 2, 2, 2, 1, 1, 2, 2, 2, 4, 4, 3, 2, 1, 2, 3, 4, 4, 3, 2, 2, 2, 1, 1, 2, 2, 2, 3, 4, 4, 4, 3, 2, 1, 2, 3, 4, 4, 4, 2, 3, 2, 2, 2, 1, 1, 2, 2, 2, 3, 2, 6, 4, 4, 4, 3, 2, 1, 2, 3, 4, 4, 4, 6, 2, 2, 3, 2, 2, 2, 1, 1, 2, 2, 2, 3, 2, 2 (list; table; graph; refs; listen; history; internal format)
OFFSET

1,4

COMMENTS

T(m,n) = number of solutions (h,k) of n=m+hk, where h>=0, k>=0. Except for initial terms every row (and column) is A000005.

EXAMPLE

Northwest corner:

1 1 2 2 3 2 4

1 1 1 2 2 3 2

2 1 1 1 2 2 3

2 2 1 1 1 2 2

3 2 2 1 1 1 2

T(8,2) counts these 4 arithmetic progressions:

2,3,4,5,6,7,8; 2,4,6,8; 2,5,8; and 2,8.

CROSSREFS

Cf. A000005.

Sequence in context: A161175 A095955 A078573 * A035176 A011793 A109649

Adjacent sequences:  A143783 A143784 A143785 * A143787 A143788 A143789

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling (ck6(AT)evansville.edu), Sep 01 2008

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Last modified February 14 08:58 EST 2012. Contains 205614 sequences.