A247524 Numbers k such that d(r,k) != d(s,k), where d(x,k) = k-th binary digit of x, r = {golden ratio}, s = {(golden ratio)/2}, and { } = fractional part.
2, 4, 8, 11, 13, 14, 17, 18, 22, 24, 26, 27, 30, 32, 33, 34, 41, 42, 43, 45, 46, 47, 48, 50, 55, 60, 61, 62, 63, 64, 69, 71, 74, 76, 79, 81, 83, 90, 92, 98, 99, 100, 103, 105, 108, 109, 111, 112, 115, 117, 118, 123, 125, 126, 127, 132, 133, 137, 138, 143
Offset: 1
Examples
r has binary digits 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 1, ... s has binary digits 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, ... so that a(1) = 2 and a(2) = 4.
Links
- Clark Kimberling, Table of n, a(n) for n = 1..2000
Crossrefs
Cf. A247523.
Programs
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Mathematica
z = 400; r1 = GoldenRatio; r = FractionalPart[r1]; s = FractionalPart[r1/2]; u = Flatten[{ConstantArray[0, -#[[2]]], #[[1]]}] &[RealDigits[r, 2, z]]; v = Flatten[{ConstantArray[0, -#[[2]]], #[[1]]}] &[RealDigits[s, 2, z]]; t = Table[If[u[[n]] == v[[n]], 1, 0], {n, 1, z}]; Flatten[Position[t, 1]] (* A247523 *) Flatten[Position[t, 0]] (* A247524 *) Module[{nn=150,gr,g2},gr=Rest[RealDigits[GoldenRatio,2,nn+1][[1]]];g2 = RealDigits[ GoldenRatio/2,2,nn][[1]];Position[Thread[{gr,g2}],?(#[[1]] != #[[2]]&),1,Heads->False]]//Flatten (* _Harvey P. Dale, Jun 28 2021 *)
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