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 1-10 of 17 results. Next

A278056 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 4; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 4.

Original entry on oeis.org

1, 2, 3, 4, 3, 5, 6, 5, 7, 6, 7, 8, 8, 10, 9, 11, 10, 11, 12, 12, 14, 11, 15, 15, 12, 17, 15, 15, 20, 15, 18, 20, 17, 20, 20, 22, 19, 23, 23, 20, 25, 21, 22, 26, 27, 24, 27, 29, 23, 29, 26, 32, 29, 23, 37, 29, 27, 38, 34, 28, 32, 35, 33, 38, 35, 33, 40, 35, 40
Offset: 1

Views

Author

Nathan Fox, Nov 10 2016

Keywords

Comments

Similar to Hofstadter's Q-sequence A005185 but with different starting values.
Much like the Hofstadter Q-sequence, it is not known if this sequence is defined for all positive n.
a(n) exists for n <= 3*10^7.

Links

Crossrefs

Cf. A005185, A278057, A278058, A278059, A278060, A278061, A278062, A278063, A278064, A278065.

Programs

  • Mathematica
    Nest[Append[#1, #1[[#2 - #1[[-1]] ]] + #1[[#2 - #1[[-2]] ]]] & @@ {#, 1 + Length@ #} &, Range@ 4, 65] (* Michael De Vlieger, Sep 26 2018 *)

A278057 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 5; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 5.

Original entry on oeis.org

1, 2, 3, 4, 5, 3, 6, 7, 5, 8, 6, 7, 9, 11, 7, 10, 14, 11, 12, 12, 10, 15, 16, 12, 14, 18, 14, 19, 15, 13, 21, 18, 14, 22, 19, 25, 18, 21, 21, 24, 26, 21, 29, 23, 25, 26, 25, 31, 23, 26, 33, 30, 28, 30, 28, 37, 27, 31, 37, 31, 25, 39
Offset: 1

Views

Author

Nathan Fox, Nov 10 2016

Keywords

Comments

Similar to Hofstadter's Q-sequence A005185 but with different starting values.
Much like the Hofstadter Q-sequence, it is not known if this sequence is defined for all positive n.
a(n) exists for n <= 3*10^7.

Links

Crossrefs

Cf. A005185, A278056, A278058, A278059, A278060, A278061, A278062, A278063, A278064, A278065.

Programs

  • Mathematica
    a[n_] := a[n] = If[0 < n < 6, n, a[n-a[n-1]] + a[n-a[n-2]]];
Array[a, 100] (* Paolo Xausa, May 29 2024 *)

A278059 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 7; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 7.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 3, 8, 9, 5, 10, 6, 7, 11, 13, 10, 8, 13, 17, 7, 16, 20, 7, 13, 19, 10, 16, 19, 12, 23, 25, 12, 24, 25, 15, 26, 30, 14, 28, 16, 26, 20, 15, 25, 30, 26, 24, 33, 29, 24, 36, 29, 21, 43, 31, 26, 35, 19, 29, 51, 17, 40, 33, 38, 28
Offset: 1

Views

Author

Nathan Fox, Nov 10 2016

Keywords

Comments

Similar to Hofstadter's Q-sequence A005185 but with different starting values.
Much like the Hofstadter Q-sequence, it is not known if this sequence is defined for all positive n.
a(n) exists for n <= 3*10^7.

Links

Crossrefs

Cf. A005185, A278056, A278057, A278058, A278060, A278061, A278062, A278063, A278064, A278065.

Programs

  • Mathematica
    a[n_] := a[n] = If[0 < n < 8, n, a[n-a[n-1]] + a[n-a[n-2]]];
Array[a, 100] (* Paolo Xausa, May 29 2024 *)

A278060 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 8; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 8.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 3, 9, 10, 5, 11, 6, 7, 12, 14, 10, 8, 14, 18, 12, 15, 8, 23, 13, 10, 17, 13, 25, 16, 19, 20, 13, 19, 29, 18, 17, 30, 24, 24, 20, 23, 26, 20, 27, 24, 26, 38, 13, 28, 38, 30, 20, 42, 35, 19, 45, 30, 32, 29, 45, 23, 32, 40
Offset: 1

Views

Author

Nathan Fox, Nov 10 2016

Keywords

Comments

Similar to Hofstadter's Q-sequence A005185 but with different starting values.
This sequence has exactly 420 terms, since a(420)=430 and computing a(421) would refer to a(-9).

Links

Crossrefs

Cf. A005185, A278056, A278057, A278058, A278059, A278061, A278062, A278063, A278064, A278065.

Programs

  • Mathematica
    a[n_] := a[n] = If[0 < n < 9, n, a[n-a[n-1]] + a[n-a[n-2]]];
Array[a, 100] (* Paolo Xausa, May 29 2024 *)

A278061 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 9; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 9.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 3, 10, 11, 5, 12, 6, 7, 13, 15, 10, 8, 15, 19, 12, 16, 14, 14, 10, 27, 12, 18, 15, 25, 23, 19, 18, 28, 19, 13, 22, 25, 17, 27, 21, 25, 24, 34, 17, 27, 44, 18, 30, 38, 18, 35, 27, 27, 36, 34, 26, 33, 45, 25, 28, 50
Offset: 1

Views

Author

Nathan Fox, Nov 10 2016

Keywords

Comments

Similar to Hofstadter's Q-sequence A005185 but with different starting values.
Much like the Hofstadter Q-sequence, it is not known if this sequence is defined for all positive n.
a(n) exists for n <= 3*10^7.

Links

Crossrefs

Cf. A005185, A278056, A278057, A278058, A278059, A278060, A278062, A278063, A278064, A278065.

Programs

  • Magma
    [n le 9 select n else Self(n-Self(n-1))+Self(n-Self(n-2)): n in [1..70]]; // Bruno Berselli, Nov 15 2016
  • Mathematica
    a[n_] := a[n] = If[0 < n < 10, n, a[n-a[n-1]] + a[n-a[n-2]]];
Array[a, 100] (* Paolo Xausa, May 29 2024 *)

A278062 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 10; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 10.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 3, 11, 12, 5, 13, 6, 7, 14, 16, 10, 8, 16, 20, 12, 17, 14, 22, 11, 21, 25, 16, 13, 17, 15, 24, 19, 26, 27, 23, 19, 30, 31, 23, 20, 33, 26, 13, 40, 28, 26, 37, 27, 20, 37, 38, 30, 38, 21, 35, 40, 22, 35, 41, 41, 24
Offset: 1

Views

Author

Nathan Fox, Nov 10 2016

Keywords

Comments

Similar to Hofstadter's Q-sequence A005185 but with different starting values.
Much like the Hofstadter Q-sequence, it is not known if this sequence is defined for all positive n.
a(n) exists for n <= 3*10^7.

Links

Crossrefs

Cf. A005185, A278056, A278057, A278058, A278059, A278060, A278061, A278063, A278064, A278065.

Programs

  • Mathematica
    a[n_] := a[n] = If[0 < n < 11, n, a[n-a[n-1]] + a[n-a[n-2]]];
Array[a, 100] (* Paolo Xausa, May 30 2024 *)

A278063 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 11; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 11.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 3, 12, 13, 5, 14, 6, 7, 15, 17, 10, 8, 17, 21, 12, 18, 14, 23, 11, 22, 26, 16, 13, 17, 15, 25, 11, 26, 35, 18, 23, 36, 24, 25, 27, 25, 25, 34, 26, 35, 26, 24, 25, 33, 30, 35, 22, 42, 17, 31, 47, 31, 30, 30
Offset: 1

Views

Author

Nathan Fox, Nov 10 2016

Keywords

Comments

Similar to Hofstadter's Q-sequence A005185 but with different starting values.
This sequence has exactly 199 terms, since a(199)=206 and computing a(200) would refer to a(-6).

Links

Crossrefs

Cf. A005185, A278056, A278057, A278058, A278059, A278060, A278061, A278062, A278064, A278065.

Programs

  • Magma
    [n le 11 select n else Self(n-Self(n-1))+Self(n-Self(n-2)): n in [1..70]]; // Bruno Berselli, Nov 15 2016
  • Mathematica
    a[n_] := a[n] = If[0 < n < 12, n, a[n-a[n-1]] + a[n-a[n-2]]];
Array[a, 100] (* Paolo Xausa, May 30 2024 *)

A278064 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 12; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 12.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 3, 13, 14, 5, 15, 6, 7, 16, 18, 10, 8, 18, 22, 12, 19, 14, 24, 11, 23, 27, 16, 13, 17, 15, 26, 20, 10, 27, 36, 20, 15, 42, 14, 31, 21, 34, 28, 15, 23, 50, 14, 31, 54, 24, 19, 23, 42, 32, 31, 34, 51, 14, 36, 61, 29, 17, 77
Offset: 1

Views

Author

Nathan Fox, Nov 10 2016

Keywords

Comments

Similar to Hofstadter's Q-sequence A005185 but with different starting values.
This sequence has exactly 69 terms, since a(69)=77 and computing a(70) would refer to a(-7).

Links

Crossrefs

Cf. A005185, A278056, A278057, A278058, A278059, A278060, A278061, A278062, A278063, A278065.

Programs

  • Mathematica
    a[n_] := a[n] = If[0 < n < 13, n, a[n-a[n-1]] + a[n-a[n-2]]];
Array[a, 69] (* Paolo Xausa, May 30 2024 *)

A278065 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 13; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 13.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 3, 14, 15, 5, 16, 6, 7, 17, 19, 10, 8, 19, 23, 12, 20, 14, 25, 11, 24, 28, 16, 13, 17, 15, 27, 20, 20, 34, 27, 24, 12, 45, 17, 27, 28, 36, 22, 28, 33, 26, 37, 30, 29, 32, 37, 31, 24, 40, 46, 15, 52, 35
Offset: 1

Views

Author

Nathan Fox, Nov 10 2016

Keywords

Comments

Similar to Hofstadter's Q-sequence A005185 but with different starting values.
Much like the Hofstadter Q-sequence, it is not known if this sequence is defined for all positive n.
a(n) exists for n <= 3*10^7.

Links

Crossrefs

Cf. A005185, A278056, A278057, A278058, A278059, A278060, A278061, A278062, A278063, A278064.

Programs

  • Mathematica
    a[n_] := a[n] = If[0 < n < 14, n, a[n-a[n-1]] + a[n-a[n-2]]];
Array[a, 100] (* Paolo Xausa, May 30 2024 *)

A373227 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 7; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 7.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 6, 8, 9, 10, 9, 11, 12, 13, 12, 14, 15, 16, 15, 17, 18, 17, 20, 18, 20, 22, 21, 21, 22, 26, 25, 23, 24, 28, 26, 29, 26, 31, 30, 32, 28, 34, 30, 37, 29, 38, 35, 37, 33, 39, 40, 38, 37, 42, 43, 40, 40, 44, 42, 47, 43, 44, 46, 51, 46, 46, 50, 50, 50, 51, 53, 50
Offset: 1

Views

Author

Nathan Fox, May 28 2024

Keywords

Comments

Similar to A278055 but with different starting values.
Much like the Hofstadter Q-sequence A005185, it is not known if this sequence is defined for all positive n.
a(n) exists for n <= 3*10^7.

Links

Crossrefs

Cf. A005185, A278055, A373228, A373229, A373230, A373231, A373232, A373233.
Similar sequences based on the Q-recurrence: A278056, A278057, A278058, A278059, A278060, A278061, A278062, A278063, A278064, A278065.

Programs

  • Mathematica
    a[n_] := a[n] = If[0 < n < 8, n, a[n-a[n-1]] + a[n-a[n-2]] + a[n-a[n-3]]];
Array[a, 100] (* Paolo Xausa, May 31 2024 *)
Showing 1-10 of 17 results. Next

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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