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A194661 Triangular array: T(n,k)=[<n*r>+<k*r>], where [ ] = floor, < > = fractional part, and r = (1+sqrt(5))/2 (the golden ratio). 2

%I #7 Mar 30 2012 18:57:43

%S 1,0,0,1,1,1,1,0,1,0,0,0,0,0,0,1,0,1,1,0,1,0,0,1,0,0,1,0,1,1,1,1,1,1,

%T 1,1,1,0,1,1,0,1,0,1,1,0,0,1,0,0,0,0,1,0,0,1,1,1,1,0,1,1,1,1,0,1,1,0,

%U 1,0,0,1,0,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,1,0,1,0,1

%N Triangular array: T(n,k)=[<n*r>+<k*r>], where [ ] = floor, < > = fractional part, and r = (1+sqrt(5))/2 (the golden ratio).

%C n-th row sum gives the number of k in [0,n] for which <n*r>+<k*r> > 1; see A194662.

%C Triangles of this sort and their row sums are sampled by the following sequences:

%C A194661-A194662: r=(1+sqrt(5))/2

%C A194663-A194665: r=sqrt(2)

%C A194666-A194668: r=sqrt(3)

%C A194669-A194671: r=sqrt(5)

%C A194675-A194678: r=e

%C A194679-A194682: r=3-sqrt(2)

%C A194683-A194686: r=(1+sqrt(3))/2

%e First 13 rows:

%e 1

%e 0 0

%e 1 1 1

%e 1 0 1 0

%e 0 0 0 0 0

%e 1 0 1 1 0 1

%e 0 0 1 0 0 1 0

%e 1 1 1 1 1 1 1 1

%e 1 0 1 1 0 1 0 1 1

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

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

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

%e 0 0 0 0 0 0 0 0 0 0 0 0 0

%t r = GoldenRatio; z = 14;

%t p[x_] := FractionalPart[x]; f[x_] := Floor[x];

%t h[n_, k_] := f[p[n*r] + p[k*r]]

%t Flatten[Table[h[n, k], {n, 1, z}, {k, 1, n}]]

%t (* A194661 *)

%t TableForm[Table[h[n, k], {n, 1, z}, {k, 1, n}]]

%t t[n_] := Sum[h[n, k], {k, 1, n}]

%t Table[t[n], {n, 1, 100}] (* A194662 *)

%Y Cf. A194662.

%K nonn,tabl

%O 1

%A _Clark Kimberling_, Sep 01 2011

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Last modified April 25 05:18 EDT 2024. Contains 371964 sequences. (Running on oeis4.)