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.

Showing 1-2 of 2 results.

A293322 Greatest integer k such that k/2^n < 1/tau, where tau = (1+sqrt(5))/2 = golden ratio.

Original entry on oeis.org

0, 1, 2, 4, 9, 19, 39, 79, 158, 316, 632, 1265, 2531, 5062, 10125, 20251, 40503, 81006, 162013, 324027, 648055, 1296111, 2592222, 5184444, 10368889, 20737779, 41475558, 82951117, 165902235, 331804471, 663608942, 1327217884, 2654435769, 5308871538
Offset: 0

Views

Author

Clark Kimberling, Oct 07 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 120; r = -1+GoldenRatio;
    Table[Floor[r*2^n], {n, 0, z}];   (* A293322 *)
    Table[Ceiling[r*2^n], {n, 0, z}]; (* A293323 *)
    Table[Round[r*2^n], {n, 0, z}]; (* A293324 *)
  • PARI
    a(n) = 2^n*(sqrt(5)-1)\2; \\ Altug Alkan, Oct 08 2017

Formula

a(n) = floor((r*2^n)), where r = (-1+sqrt(5))/2.
a(n) = A293323(n) - 1.

A293323 Least integer k such that k/2^n > 1/tau, where tau = (1+sqrt(5))/2 = golden ratio.

Original entry on oeis.org

1, 2, 3, 5, 10, 20, 40, 80, 159, 317, 633, 1266, 2532, 5063, 10126, 20252, 40504, 81007, 162014, 324028, 648056, 1296112, 2592223, 5184445, 10368890, 20737780, 41475559, 82951118, 165902236, 331804472, 663608943, 1327217885, 2654435770, 5308871539
Offset: 0

Views

Author

Clark Kimberling, Oct 07 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 120; r = -1+GoldenRatio;
    Table[Floor[r*2^n], {n, 0, z}];   (* A293322 *)
    Table[Ceiling[r*2^n], {n, 0, z}]; (* A293323 *)
    Table[Round[r*2^n], {n, 0, z}];   (* A293324 *)
  • PARI
    a(n) = ceil(2^(n-1)*(sqrt(5)-1)); \\ Altug Alkan, Oct 08 2017

Formula

a(n) = ceiling(r*2^n), where r = (-1+sqrt(5))/2.
a(n) = A293322(n) + 1.
Showing 1-2 of 2 results.