A143902 Rectangular array R by antidiagonals: R(m,n) = number of black squares

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.

Links

Table of n, a(n) for n=1..83.

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

Adjacent sequences: A143899 A143900 A143901 * A143903 A143904 A143905

Keyword

nonn,tabl

Author

Clark Kimberling, Sep 04 2008

Status

approved