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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 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The first column is equal 0 when n is a square greater than 1. The rest of the array is equal to the A143104. The determinant of this array is A002819.

LINKS

Table of n, a(n) for n=1..105.

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-Fran├žois Alcover, Dec 05 2013 *)

CROSSREFS

Cf. A143104, A002819, A174854, A174852.

Sequence in context: A127244 A144778 A143142 * A175608 A285467 A194679

Adjacent sequences:  A174853 A174854 A174855 * A174857 A174858 A174859

KEYWORD

nonn,tabl

AUTHOR

Mats Granvik, Mar 31 2010

STATUS

approved

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Last modified September 22 22:13 EDT 2021. Contains 347608 sequences. (Running on oeis4.)