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A143902
Rectangular array R by antidiagonals: R(m,n) = number of black squares
1
0, 1, 1, 1, 2, 1, 2, 3, 3, 2, 2, 4, 4, 4, 2, 3, 5, 6, 6, 5, 3, 3, 6, 7, 8, 7, 6, 3, 4, 7, 9, 10, 10, 9, 7, 4, 4, 8, 10, 12, 12, 12, 10, 8, 4, 5, 9, 12, 14, 15, 15, 14, 12, 9, 5, 5, 10, 13, 16, 17, 18, 17, 16, 13, 10, 5, 6, 11, 15, 18, 20, 21, 21, 20, 18, 15, 11, 6, 6, 12, 16, 20, 22
OFFSET
1,5
COMMENTS
Antidiagonal sums: (2,4,10,16,28,40,60,80,...)=A006584 (conjectured).
Diagonals: A007590, A000217.
FORMULA
R(m,n)=Floor(mn/2).
EXAMPLE
Northwest corner:
0 1 1 2 2 3 3 4
1 2 3 4 5 6 7 8
1 3 4 6 7 9 10 12
2 4 6 8 10 12 14 16
CROSSREFS
Cf. A143901.
Sequence in context: A357743 A058063 A232094 * A085472 A054242 A033767
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Sep 04 2008
STATUS
approved