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 1-7 of 7 results.

A026264 (1/2)*(s(n) + 1), where s(n) is the n-th odd number in A026262.

Original entry on oeis.org

1, 2, 3, 4, 6, 7, 5, 8, 9, 15, 10, 16, 11, 17, 18, 12, 13, 14, 25, 26, 27, 28, 19, 20, 21, 22, 34, 23, 35, 36, 24, 37, 44, 29, 45, 30, 46, 47, 31, 32, 33, 53, 54, 55, 56, 38, 39, 40, 41, 63, 42, 64, 65, 43, 66, 72, 73, 48, 74, 49, 75, 50, 51
Offset: 1

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Author

Keywords

A026266 a(n) = (1/2)*s(n), where s = A026262.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 10, 7, 11, 12, 8, 13, 9, 19, 20, 21, 14, 22, 23, 15, 16, 17, 18, 29, 30, 31, 32, 24, 38, 25, 39, 26, 40, 41, 27, 42, 28, 48, 49, 50, 33, 51, 34, 35, 36, 37, 57, 58, 59, 60, 61, 43, 67, 44, 68, 45, 69, 70, 46, 47, 76, 77, 78
Offset: 1

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Author

Keywords

A026263 a(n) = |s(n) - n|, where s = A026262.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 2, 3, 3, 3, 3, 4, 3, 4, 5, 4, 5, 4, 6, 5, 6, 5, 6, 7, 6, 8, 6, 8, 6, 8, 7, 8, 9, 8, 10, 8, 10, 8, 10, 8, 10, 9, 11, 12, 10, 12, 10, 12, 10, 13, 10, 13, 14, 11, 14, 12, 15, 12, 15, 12, 15, 16, 13, 16, 13, 17, 14, 17, 14, 17
Offset: 1

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Author

Keywords

A022839 Beatty sequence for sqrt(5).

Original entry on oeis.org

2, 4, 6, 8, 11, 13, 15, 17, 20, 22, 24, 26, 29, 31, 33, 35, 38, 40, 42, 44, 46, 49, 51, 53, 55, 58, 60, 62, 64, 67, 69, 71, 73, 76, 78, 80, 82, 84, 87, 89, 91, 93, 96, 98, 100, 102, 105, 107, 109, 111, 114, 116, 118, 120, 122, 125, 127, 129, 131, 134, 136
Offset: 1

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Keywords

Crossrefs

Cf. A026262; complement of A108598.

Programs

Formula

a(n) = floor(n*sqrt(5)). - G. C. Greubel, Sep 28 2018

A108598 a(n) = floor(n*((5+sqrt(5))/4)).

Original entry on oeis.org

1, 3, 5, 7, 9, 10, 12, 14, 16, 18, 19, 21, 23, 25, 27, 28, 30, 32, 34, 36, 37, 39, 41, 43, 45, 47, 48, 50, 52, 54, 56, 57, 59, 61, 63, 65, 66, 68, 70, 72, 74, 75, 77, 79, 81, 83, 85, 86, 88, 90, 92, 94, 95, 97, 99, 101, 103, 104, 106, 108, 110, 112, 113, 115, 117, 119, 121
Offset: 1

Views

Author

Reinhard Zumkeller, Jun 11 2005

Keywords

Comments

Beatty sequence for (5+sqrt(5))/4; complement of A022839.

Crossrefs

Programs

  • Magma
    [Floor(n*(5+Sqrt(5))/4): n in [1..80]]; // G. C. Greubel, Oct 20 2023
    
  • Mathematica
    With[{c=(5+Sqrt[5])/4},Floor[c Range[80]]] (* Harvey P. Dale, Jul 20 2022 *)
  • SageMath
    [int(n*sqrt(5)*golden_ratio/2) for n in range(1,81)] # G. C. Greubel, Oct 20 2023

A026250 Beginning with the natural numbers, swap [ k*sqrt(2) ] and [ k*(2 + sqrt(2)) ], for all k >= 1.

Original entry on oeis.org

3, 6, 1, 10, 13, 2, 17, 20, 23, 4, 27, 30, 5, 34, 37, 40, 7, 44, 47, 8, 51, 54, 9, 58, 61, 64, 11, 68, 71, 12, 75, 78, 81, 14, 85, 88, 15, 92, 95, 16, 99, 102, 105, 18, 109, 112, 19, 116, 119, 122, 21, 126, 129, 22, 133, 136, 139, 24, 143, 146
Offset: 1

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Author

Keywords

Comments

Self-inverse integer permutation induced by Beatty sequences for sqrt(2) and 2+sqrt(2). - Reinhard Zumkeller, Jun 11 2005

Crossrefs

Formula

a(A001951(n)) = A001952(n) and a(A001952(n)) = A001951(n). - Reinhard Zumkeller, Jun 11 2005

A026255 Beginning with the natural numbers, swap [ k*sqrt(3) ] and [ (k/2)*(3 + sqrt(3)) ], for all k >= 1.

Original entry on oeis.org

2, 1, 4, 3, 7, 9, 5, 11, 6, 14, 8, 16, 18, 10, 21, 12, 23, 13, 26, 28, 15, 30, 17, 33, 35, 19, 37, 20, 40, 22, 42, 44, 24, 47, 25, 49, 27, 52, 54, 29, 56, 31, 59, 32, 61, 63, 34, 66, 36, 68, 70, 38, 73, 39, 75, 41, 78, 80, 43, 82, 45, 85, 46
Offset: 1

Views

Author

Keywords

Comments

Self-inverse integer permutation induced by Beatty sequences for sqrt(3) and (3+sqrt(3))/2. - Reinhard Zumkeller, Jun 11 2005

Crossrefs

Formula

a(A022838(n)) = A054406(n) and a(A054406(n)) = A022838(n). - Reinhard Zumkeller, Jun 11 2005
Showing 1-7 of 7 results.