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.

A191340 (A022839 mod 2)+(A108598 mod 2).

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 1, 0, 0, 1, 1, 2, 2, 2, 1, 0, 0, 0, 0, 1, 2, 2, 2, 2, 1, 0, 0, 0, 1, 1, 2, 2, 1, 1, 1, 0, 0, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 0, 0, 1, 1, 1, 2, 2, 1, 1, 0, 0, 0, 1, 2, 2, 2, 2, 1, 0, 0, 0, 0, 1, 2, 2, 2, 1, 1, 0, 0, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 0, 1, 1, 1, 2, 2, 1, 1, 0, 0, 0, 1, 2, 2, 2, 2, 1, 0, 0, 0, 0, 1, 2, 2, 2, 1, 1, 0, 0, 1, 1, 1, 2, 2, 1, 1, 1, 0, 1
Offset: 1

Views

Author

Clark Kimberling, Jun 01 2011

Keywords

Comments

Let r=sqrt(5) and s=r/(r-1). There numbers yield the following two complementary Beatty sequences:
A022839(n)=[nr], A108598(n)=[ns], where [ ]=floor.
A191340(n)=the number of odd numbers in {[nr], [ns]}.

Crossrefs

Programs

  • Mathematica
    r = Sqrt[5]; s = r/(r - 1); h = 120;
    u = Table[Floor[n*r], {n, 1, h}] (* A022839 *)
    v = Table[Floor[n*s], {n, 1, h}] (* A108598 *)
    w = Mod[u, 2] + Mod[v, 2] (* A191340 *)
    Flatten[Position[w, 0]]  (* A191380 *)
    Flatten[Position[w, 1]]  (* A191381 *)
    Flatten[Position[w, 2]]  (* A191382 *)

Formula

a(n)=([nr] mod 2)+([ns] mod 2), where r=sqrt(5), s=r/(r-1), [ ]=floor.

A191380 Positions of 0 in A191340.

Original entry on oeis.org

9, 10, 17, 18, 19, 20, 27, 28, 29, 37, 38, 51, 52, 60, 61, 62, 69, 70, 71, 72, 79, 80, 94, 102, 103, 104, 111, 112, 113, 114, 121, 122, 131, 136, 145, 146, 153, 154, 155, 156, 163, 164, 165, 173, 178, 187, 188, 195, 196, 197, 198, 205, 206, 207, 215, 216, 229, 230, 238, 239, 240, 247, 248, 249, 257, 258, 272, 280, 281, 282, 289, 290
Offset: 1

Views

Author

Clark Kimberling, Jun 01 2011

Keywords

Comments

See A191340.

Crossrefs

Cf. A191340.
Cf. A191381, A191382 (positions of 1 and 2 in the same).

Programs

A191382 Positions of 2 in A191340.

Original entry on oeis.org

5, 13, 14, 15, 22, 23, 24, 25, 32, 33, 42, 47, 56, 57, 64, 65, 66, 67, 74, 75, 76, 84, 89, 98, 99, 106, 107, 108, 109, 116, 117, 118, 126, 127, 140, 141, 149, 150, 151, 158, 159, 160, 168, 169, 183, 191, 192, 193, 200, 201, 202, 203, 210, 211, 220, 225, 233, 234, 235, 242, 243, 244, 245, 252, 253, 254, 262, 267, 276, 277, 284, 285
Offset: 1

Views

Author

Clark Kimberling, Jun 01 2011

Keywords

Comments

See A191340.

Crossrefs

Cf. A191340.
Cf. A191380, A191381 (positions of 0 and 1 in the same).

Programs

Showing 1-3 of 3 results.