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A194685
Triangular array: T(n,k)=[<n*r>+<k*r>], where [ ] = floor, < > = fractional part, and r=(1+sqrt(3))/2.
4
0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1
OFFSET
1
COMMENTS
n-th row sum gives number of k in [0,1] for which <n*r>+<k*r> > 1; see A194686.
EXAMPLE
First twelve rows:
0
1 1
0 0 0
0 1 0 0
1 1 0 1 1
0 0 0 0 1 0
0 1 0 1 1 0 1
1 1 1 1 1 1 1 1
0 1 0 0 1 0 0 1 0
1 1 0 1 1 0 1 1 0 1
0 0 0 0 0 0 0 0 0 0 0
0 1 0 0 1 0 0 1 0 1 0 0
MATHEMATICA
r = 1/2 + Sqrt[3]/2; z = 15;
p[x_] := FractionalPart[x]; f[x_] := Floor[x];
w[n_, k_] := p[r^n] + p[r^k] - p[r^n + r^k]
Flatten[Table[w[n, k], {n, 1, z}, {k, 1, n}]]
(* A194683 *)
TableForm[Table[w[n, k], {n, 1, z}, {k, 1, n}]]
s[n_] := Sum[w[n, k], {k, 1, n}]
Table[s[n], {n, 1, 100}] (* A194684 *)
h[n_, k_] := f[p[n*r] + p[k*r]]
Flatten[Table[h[n, k], {n, 1, z}, {k, 1, n}]]
(* A194685 *)
TableForm[Table[h[n, k], {n, 1, z}, {k, 1, n}]]
t[n_] := Sum[h[n, k], {k, 1, n}]
Table[t[n], {n, 1, 100}] (* A194686 *)
CROSSREFS
Cf. A194686.
Sequence in context: A171386 A189816 A342000 * A182582 A125720 A095130
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Sep 01 2011
STATUS
approved