cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A200651 Number of equal bit-runs in Stolarsky Representation of n.

Original entry on oeis.org

1, 1, 1, 2, 1, 3, 2, 1, 2, 3, 3, 2, 1, 4, 3, 3, 2, 3, 3, 2, 1, 2, 5, 3, 4, 3, 4, 3, 3, 2, 3, 3, 2, 1, 4, 3, 5, 4, 3, 5, 4, 3, 2, 5, 3, 4, 3, 4, 3, 3, 2, 3, 3, 2, 1, 2, 5, 3, 6, 5, 5, 4, 3, 4, 5, 5, 4, 3, 4, 3, 5, 4, 3, 5, 4, 3, 2, 5, 3, 4, 3, 4, 3, 3, 2, 3, 3
Offset: 1

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Author

Casey Mongoven, Nov 19 2011

Keywords

Comments

For the Stolarsky representation of n, see the C. Mongoven link.

Examples

			The Stolarsky representation of 19 is 11101. This has 3 equal bit-runs: '111', '0' and '1'. So a(19) = 3.
		

Crossrefs

Programs

  • Mathematica
    stol[n_] := stol[n] = If[n == 1, {}, If[n != Round[Round[n/GoldenRatio]*GoldenRatio], Join[stol[Floor[n/GoldenRatio^2] + 1], {0}], Join[stol[Round[n/GoldenRatio]], {1}]]];
    a[n_] := If[n == 1, 1, Length[Split[stol[n]]]]; Array[a, 100] (* Amiram Eldar, Jul 07 2023 *)
  • PARI
    stol(n) = {my(phi=quadgen(5)); if(n==1, [], if(n != round(round(n/phi)*phi), concat(stol(floor(n/phi^2) + 1), [0]), concat(stol(round(n/phi)), [1])));}
    a(n) = {my(s = stol(n), c = 1); for(k = 1, #s-1, if(s[k+1] != s[k], c++)); c; } \\ Amiram Eldar, Jul 07 2023

Extensions

More terms from Amiram Eldar, Jul 07 2023