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.

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A137803 a(n) = floor(n*(sqrt(2) + 1/2)).

Original entry on oeis.org

1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 112, 114, 116, 118, 120, 122, 124, 126
Offset: 1

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Author

Reinhard Zumkeller, Feb 11 2008

Keywords

Comments

a(n) = A059533(n) for n <= 34;
Beatty sequence for sqrt(2) + 1/2; complement of A137804;
a(n) = A137805(A137804(n)) and A137805(a(n)) = A137804(n).

Crossrefs

Programs

  • Magma
    [Floor(n*(Sqrt(2)+1/2)): n in [1..50]]; // G. C. Greubel, Jan 27 2018
    
  • Mathematica
    Floor[Range[80](Sqrt[2]+1/2)]  (* Harvey P. Dale, Mar 24 2011 *)
  • PARI
    for(n=1,50, print1(floor(n*(sqrt(2)+1/2)), ", ")) \\ G. C. Greubel, Jan 27 2018
    
  • Python
    from math import isqrt
    def A137803(n): return (n>>1)+(m:=isqrt(r:=n*n<<1))+(n&1)*int(r-m*(m+1)>=1) # Chai Wah Wu, Aug 03 2022

A137804 a(n) = floor(n*(4*sqrt(2)+9)/7).

Original entry on oeis.org

2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 134, 136
Offset: 1

Views

Author

Reinhard Zumkeller, Feb 11 2008

Keywords

Comments

a(n) = A059534(n) for n <= 31;
Beatty sequence for (4*Sqrt(2)+9)/7; complement of A137803;
a(n) = A137805(A137803(n)) and A137805(a(n)) = A137803(n).

Crossrefs

Programs

  • Magma
    [Floor(n*(4*Sqrt(2)+9)/7): n in [1..100]]; // G. C. Greubel, Mar 28 2018
  • Maple
    [seq(floor(n*(4*(sqrt(2))+9)/7),n=1..70)]; # Muniru A Asiru, Mar 29 2018
  • Mathematica
    Table[Floor[n*(4*Sqrt[2]+9)/7], {n,1,100}] (* G. C. Greubel, Mar 28 2018 *)
  • PARI
    for(n=1,100, print1(floor(n*(4*sqrt(2)+9)/7), ", ")) \\ G. C. Greubel, Mar 28 2018
    
Showing 1-2 of 2 results.