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A174856
Square array read by antidiagonals up. Redheffer type matrix. T(1,1)=1 and T(n,1) = A049240.
1
1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1
OFFSET
1,1
COMMENTS
The first column is equal to 0 when n is a square greater than 1. The rest of the array is equal to A143104. The determinant of this array is A002819.
EXAMPLE
The array begins:
1,1,1,1,1,1,1,1,1,1
1,1,0,0,0,0,0,0,0,0
1,0,1,0,0,0,0,0,0,0
0,1,0,1,0,0,0,0,0,0
1,0,0,0,1,0,0,0,0,0
1,1,1,0,0,1,0,0,0,0
1,0,0,0,0,0,1,0,0,0
1,1,0,1,0,0,0,1,0,0
0,0,1,0,0,0,0,0,1,0
1,1,0,0,1,0,0,0,0,1
MATHEMATICA
t[1, 1] = 1; t[n_, 1] := Boole[!IntegerQ[Sqrt[n]]]; t[n_, k_] := Boole[n == 1 || Mod[n, k] == 0]; Table[t[n - k + 1, k], {n, 1, 14}, {k, 1, n}] // Flatten (* Jean-François Alcover, Dec 05 2013 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Mats Granvik, Mar 31 2010
STATUS
approved