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Search: id:A156826
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A156826 Square array read by anti diagonals up. +0
2
1, 2, -1, 3, 1, -1, 4, -1, 0, -1, 5, 2, 1, 0, -1, 6, -2, -1, 0, 0, -1, 7, 3, -1, 1, 0, 0, -1, 8, -3, 2, -1, 0, 0, 0, -1, 9, 4, -2, -1, 1, 0, 0, 0, -1, 10, -4, -2, -1, -1, 0, 0, 0, 0, -1, 11, 5, 3, 2, -1, 1, 0, 0, 0, 0, -1, 12, -5, -3, -2, -1, -1, 0, 0, 0, 0, 0, -1, 13, 6, -3, -2, -1, -1, 1, 0, 0 (list; table; graph; listen)
OFFSET

1,2

COMMENT

This square array is the same as A126988 except that the first row is A153881.

Replace the zeros with -n/k. That is, the fraction of the row index divided by the column index with a negative sign. Then swap the element in the lower right corner with the element in the upper right corner and calculate the determinant. The result appears to be sequence A156827.

EXAMPLE

Table begins:

1.-1.-1.-1.-1.-1.-1.-1.-1.-1.-1.-1.-1

2..1..0..0..0..0..0..0..0..0..0..0..0

3..0..1..0..0..0..0..0..0..0..0..0..0

4..2..0..1..0..0..0..0..0..0..0..0..0

5..0..0..0..1..0..0..0..0..0..0..0..0

6..3..2..0..0..1..0..0..0..0..0..0..0

7..0..0..0..0..0..1..0..0..0..0..0..0

8..4..0..2..0..0..0..1..0..0..0..0..0

9..0..3..0..0..0..0..0..1..0..0..0..0

10.5..0..0..2..0..0..0..0..1..0..0..0

11.0..0..0..0..0..0..0..0..0..1..0..0

12.6..4..3..0..2..0..0..0..0..0..1..0

13.0..0..0..0..0..0..0..0..0..0..0..1

PROGRAM

(Other) (Excel cell formula) =rounddown(if(mod(row(); column())=0; row()/column(); -row()/column())*if(row()=1; column(); 1); 0)

(Excel cell formula) with fractions: =if(mod(row(); column())=0; row()/column(); -row()/column())*if(row()=1; column(); 1)

CROSSREFS

Cf. A126988, A153881, A156827.

Sequence in context: A006346 A088742 A144220 this_sequence A130296 A126705 A113924

Adjacent sequences: A156823 A156824 A156825 this_sequence A156827 A156828 A156829

KEYWORD

sign,tabl

AUTHOR

Mats Granvik (mats.granvik(AT)abo.fi), Feb 16 2009

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Last modified December 7 23:50 EST 2009. Contains 170430 sequences.


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