The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A247522 Numbers k such that d(r,k) = 1 and d(s,k) = 1, where d(x,k) = k-th binary digit of x, r = {golden ratio}, s = {(golden ratio)/2}, and { } = fractional part. 4
 1, 5, 6, 7, 12, 15, 16, 19, 20, 21, 25, 28, 29, 35, 36, 37, 38, 39, 40, 51, 52, 53, 54, 65, 66, 67, 68, 72, 73, 77, 78, 82, 91, 101, 102, 106, 107, 110, 113, 114, 124, 151, 152, 155, 160, 161, 162, 163, 164, 168, 169, 179, 180, 193, 194, 195, 196, 197, 203 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Every positive integer lies in exactly one of these: A247519, A247520, A247521. LINKS Clark Kimberling, Table of n, a(n) for n = 1..1000 EXAMPLE 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) = 1 and a(2) = 5. 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]] t1 = Table[If[u[[n]] == 0 && v[[n]] == 0, 1, 0], {n, 1, z}]; t2 = Table[If[u[[n]] == 0 && v[[n]] == 1, 1, 0], {n, 1, z}]; t3 = Table[If[u[[n]] == 1 && v[[n]] == 0, 1, 0], {n, 1, z}]; t4 = Table[If[u[[n]] == 1 && v[[n]] == 1, 1, 0], {n, 1, z}]; Flatten[Position[t1, 1]] (* A247519 *) Flatten[Position[t2, 1]] (* A247520 *) Flatten[Position[t3, 1]] (* A247521 *) Flatten[Position[t4, 1]] (* A247522 *) CROSSREFS Cf. A247519, A247520, A247521. Sequence in context: A022566 A047320 A327301 * A011761 A106745 A165776 Adjacent sequences:  A247519 A247520 A247521 * A247523 A247524 A247525 KEYWORD nonn,easy,base AUTHOR Clark Kimberling, Sep 19 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 18 04:48 EST 2020. Contains 332011 sequences. (Running on oeis4.)