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 1-3 of 3 results.

A293404 Least integer k such that k/n^2 > (3 + sqrt(5))/2 (the golden ratio).

Original entry on oeis.org

0, 3, 11, 24, 42, 66, 95, 129, 168, 213, 262, 317, 377, 443, 514, 590, 671, 757, 849, 946, 1048, 1155, 1268, 1385, 1508, 1637, 1770, 1909, 2053, 2202, 2357, 2516, 2681, 2852, 3027, 3208, 3393, 3585, 3781, 3983, 4189, 4401, 4619, 4841, 5069, 5302, 5540, 5784
Offset: 0

Views

Author

Clark Kimberling, Oct 11 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 120; r = 1+GoldenRatio;
    Table[Floor[r*n^2], {n, 0, z}];   (* A293403 *)
    Table[Ceiling[r*n^2], {n, 0, z}]; (* A293404 *)
    Table[Round[r*n^2], {n, 0, z}];   (* A293405 *)

Formula

a(n) = ceiling(r*n^2), where r = (3 + sqrt(5))/2.
a(n) = A293403(n) + 1 for n > 0.

A293405 The integer k that minimizes |k/n^2 - tau^2|, where tau = (1+sqrt(5))/2 (golden ratio).

Original entry on oeis.org

0, 3, 10, 24, 42, 65, 94, 128, 168, 212, 262, 317, 377, 442, 513, 589, 670, 757, 848, 945, 1047, 1155, 1267, 1385, 1508, 1636, 1770, 1909, 2053, 2202, 2356, 2516, 2681, 2851, 3026, 3207, 3393, 3584, 3780, 3982, 4189, 4401, 4618, 4841, 5069, 5302, 5540, 5783
Offset: 0

Views

Author

Clark Kimberling, Oct 11 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 120; r = 1+GoldenRatio;
    Table[Floor[r*n^2], {n, 0, z}];   (* A293403 *)
    Table[Ceiling[r*n^2], {n, 0, z}]; (* A293404 *)
    Table[Round[r*n^2], {n, 0, z}];   (* A293405 *)

Formula

a(n) = floor(1/2 + tau*n^2).
a(n) = A293403(n) if (fractional part of (1+tau)*n^2) < 1/2, else a(n) = A293404(n).

A293407 Least integer k such that k/n^2 > (-1 + sqrt(5))/2 (the golden ratio).

Original entry on oeis.org

0, 1, 3, 6, 10, 16, 23, 31, 40, 51, 62, 75, 89, 105, 122, 140, 159, 179, 201, 224, 248, 273, 300, 327, 356, 387, 418, 451, 485, 520, 557, 594, 633, 674, 715, 758, 801, 847, 893, 941, 989, 1039, 1091, 1143, 1197, 1252, 1308, 1366, 1424, 1484, 1546, 1608, 1672
Offset: 0

Views

Author

Clark Kimberling, Oct 11 2017

Keywords

Crossrefs

Programs

  • Mathematica
    z = 120; r = -1+GoldenRatio;
    Table[Floor[r*n^2], {n, 0, z}];   (* A152738 *)
    Table[Ceiling[r*n^2], {n, 0, z}]; (* A293407 *)
    Table[Round[r*n^2], {n, 0, z}];   (* A293408 *)

Formula

a(n) = ceiling(r*n^2), where r = (-1 + sqrt(5))/2.
a(n) = A152738(n) + 1 for n > 0.
Showing 1-3 of 3 results.