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.

A026309 a(n) = n-th nonnegative integer k satisfying sin(k) < sin(k+1).

Original entry on oeis.org

0, 1, 5, 6, 7, 11, 12, 13, 17, 18, 19, 24, 25, 26, 30, 31, 32, 36, 37, 38, 42, 43, 44, 45, 49, 50, 51, 55, 56, 57, 61, 62, 63, 68, 69, 70, 74, 75, 76, 80, 81, 82, 86, 87, 88, 89, 93, 94, 95, 99, 100, 101, 105, 106, 107, 112, 113, 114, 118
Offset: 1

Views

Author

Keywords

Comments

The sequences A026309, A246297, A246298, A246299 partition the nonnegative integers.

Crossrefs

Cf. A246297, A246298, A246299, A246293 (complement of A026309).

Programs

  • Mathematica
    z = 500; f[x_] := f[x] = Sin[x]; t = Range[0, z];
    Select[t, f[#] < f[# + 1] &]  (* A026309 *)
    Select[t, f[#] > f[# + 1] < f[# + 2] &]  (* A246297 *)
    Select[t, f[#] > f[# + 1] > f[# + 2] < f[# + 3] &]  (* A246298 *)
    Select[t, f[#] > f[# + 1] > f[# + 2] > f[# + 3] < f[# + 4] &] (* A246299 *)

Formula

a(n) ~ 2n by the Equidistribution Theorem. - Charles R Greathouse IV, Dec 11 2024

Extensions

Comment, Mathematica, and Crossrefs by Clark Kimberling, Aug 21 2014

A246297 Numbers k such that sin(k) > sin(k+1) < sin(k+2).

Original entry on oeis.org

4, 10, 16, 23, 29, 35, 41, 48, 54, 60, 67, 73, 79, 85, 92, 98, 104, 111, 117, 123, 129, 136, 142, 148, 155, 161, 167, 173, 180, 186, 192, 198, 205, 211, 217, 224, 230, 236, 242, 249, 255, 261, 268, 274, 280, 286, 293, 299, 305, 312, 318, 324, 330, 337, 343
Offset: 1

Views

Author

Clark Kimberling, Aug 21 2014

Keywords

Comments

The sequences A026309, A246297, A246298, A246299 partition the nonnegative integers.
Numbers like 20, 64, 108, 152,... are in none of these 4 sequences. - R. J. Mathar, May 18 2020

Crossrefs

Cf. A026309, A246298, A246299, A246293 (complement of A026309).

Programs

  • Mathematica
    z = 500; f[x_] := f[x] = Sin[x]; t = Range[0, z];
    Select[t, f[#] < f[# + 1] &]  (* A026309 *)
    Select[t, f[#] > f[# + 1] < f[# + 2] &]  (* A246297 *)
    Select[t, f[#] > f[# + 1] > f[# + 2] < f[# + 3] &]  (* A246298 *)
    Select[t, f[#] > f[# + 1] > f[# + 2] > f[# + 3] < f[# + 4] &] (* A246299 *)

Extensions

Corrected signs in NAME. - R. J. Mathar, May 18 2020

A246299 Numbers k such that sin(k) > sin(k+1) > sin(k+2) > sin(k+3) < sin(k+4).

Original entry on oeis.org

2, 8, 14, 21, 27, 33, 39, 46, 52, 58, 65, 71, 77, 83, 90, 96, 102, 109, 115, 121, 127, 134, 140, 146, 153, 159, 165, 171, 178, 184, 190, 196, 203, 209, 215, 222, 228, 234, 240, 247, 253, 259, 266, 272, 278, 284, 291, 297, 303, 310, 316, 322, 328, 335, 341
Offset: 1

Views

Author

Clark Kimberling, Aug 21 2014

Keywords

Comments

The sequences A026309, A246297, A246298, A246299 partition the nonnegative integers.
Numbers like 20, 64, 108, 152, 177, 221, 265, 309, ... are in none of these 4 sequences. - R. J. Mathar, May 18 2020

Crossrefs

Cf. A026309, A246297, A246298, A246293 (complement of A026309).

Programs

Extensions

Corrected signs in NAME. - R. J. Mathar, May 18 2020
Showing 1-3 of 3 results.