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A194393 Numbers n such that sum{<1/2+k*r>-<k*r> : 1<=k<=n}=0, where r=sqrt(13) and < > denotes fractional part. 4
2, 4, 6, 8, 24, 26, 28, 30, 32, 38, 40, 42, 44, 46, 62, 64, 66, 68, 70, 76, 78, 80, 82, 84, 100, 102, 104, 106, 108, 110, 112, 138, 140, 142, 144, 146, 148, 150, 176, 178, 180, 182, 184, 186, 188, 204, 206, 208, 210, 212, 218, 220, 222, 224, 226, 242, 244 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See A194368.

LINKS

Table of n, a(n) for n=1..57.

MATHEMATICA

r = Sqrt[13]; c = 1/2;

x[n_] := Sum[FractionalPart[k*r], {k, 1, n}]

y[n_] := Sum[FractionalPart[c + k*r], {k, 1, n}]

t1 = Table[If[y[n] < x[n], 1, 0], {n, 1, 400}];

Flatten[Position[t1, 1]]       (* A194392 *)

t2 = Table[If[y[n] == x[n], 1, 0], {n, 1, 300}];

Flatten[Position[t2, 1]]       (* A194393 *)

t3 = Table[If[y[n] > x[n], 1, 0], {n, 1, 100}];

Flatten[Position[t3, 1]]       (* A194394 *)

CROSSREFS

Cf. A194368.

Sequence in context: A029951 A062287 A189153 * A119260 A219616 A067732

Adjacent sequences:  A194390 A194391 A194392 * A194394 A194395 A194396

KEYWORD

nonn

AUTHOR

Clark Kimberling, Aug 23 2011

STATUS

approved

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Last modified May 24 06:53 EDT 2019. Contains 323529 sequences. (Running on oeis4.)