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A174856 Square array read by antidiagonals up. Redheffer type matrix. T(1,1)=1 and T(n,1) = A049240. 1

%I #11 Mar 23 2024 17:31:28

%S 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,

%T 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,

%U 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

%N Square array read by antidiagonals up. Redheffer type matrix. T(1,1)=1 and T(n,1) = A049240.

%C 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.

%e The array begins:

%e 1,1,1,1,1,1,1,1,1,1

%e 1,1,0,0,0,0,0,0,0,0

%e 1,0,1,0,0,0,0,0,0,0

%e 0,1,0,1,0,0,0,0,0,0

%e 1,0,0,0,1,0,0,0,0,0

%e 1,1,1,0,0,1,0,0,0,0

%e 1,0,0,0,0,0,1,0,0,0

%e 1,1,0,1,0,0,0,1,0,0

%e 0,0,1,0,0,0,0,0,1,0

%e 1,1,0,0,1,0,0,0,0,1

%t 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 *)

%Y Cf. A143104, A002819, A174854, A174852.

%K nonn,tabl

%O 1,1

%A _Mats Granvik_, Mar 31 2010

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Last modified July 20 23:17 EDT 2024. Contains 374461 sequences. (Running on oeis4.)