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.

A200714 Stolarsky representation interpreted as binary to decimal integers.

Original entry on oeis.org

0, 1, 3, 2, 7, 5, 6, 15, 4, 11, 13, 14, 31, 10, 9, 23, 12, 27, 29, 30, 63, 8, 21, 19, 22, 47, 26, 25, 55, 28, 59, 61, 62, 127, 20, 17, 43, 18, 39, 45, 46, 95, 24, 53, 51, 54, 111, 58, 57, 119, 60, 123, 125, 126, 255, 16, 41, 35, 42, 87, 37, 38, 79, 44, 91, 93
Offset: 1

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Author

Casey Mongoven, Nov 20 2011

Keywords

Comments

See explanation of Stolarsky representations in the C. Mongoven link.

Examples

			The Stolarsky representation of 19 is 11101. In binary this is equal to 29. So a(19) = 29.
		

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_] := FromDigits[stol[n], 2]; Array[a, 100] (* Amiram Eldar, Jul 07 2023 *)
  • PARI
    a(n) = {if (n == 1, return (0)); tau = (1 + sqrt(5))/2; mn = 0; while ((m = round(mn*tau)) < n, mn++;); if (m == n, return (2*a(mn)+1)); mn = 0; while ((m = floor(mn*(1+tau)-tau/2)) < n, mn++;); if (m == n, return (2*a(mn))); error("neither A nor B !!");} \\ (cf C. Mongoven link) Michel Marcus, May 21 2013, Sep 02 2013
    
  • 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) = fromdigits(stol(n), 2); \\ Amiram Eldar, Jul 07 2023

Formula

From Amiram Eldar, Jul 07 2023: (Start)
A000120(a(n)) = A200649(n).
A023416(a(n)) = A200650(n).
A070939(a(n)) = A200648(n).
A005811(a(n)) = A200651(n). (End)
Conjecture: a(n) = A367306(A358654(n-1)). - Mikhail Kurkov, Oct 17 2024

Extensions

More terms from Amiram Eldar, Jul 07 2023