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.

A187396 a(n) = floor(s*n), where s =-2 + sqrt(10); complement of A187395.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 22, 23, 24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 36, 37, 38, 39, 40, 41, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 72, 73, 74, 75, 76, 77, 79, 80, 81, 82, 83, 84, 86, 87, 88, 89, 90, 91, 92, 94, 95, 96, 97, 98, 99, 101, 102, 103, 104, 105, 106, 108, 109, 110, 111, 112, 113, 115, 116
Offset: 1

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Author

Clark Kimberling, Mar 09 2011

Keywords

Comments

A187395 and A187396 are the Beatty sequences based on r = 4 + sqrt(10) and s = -2 + sqrt(10); 1/r + 1/s = 1.

Crossrefs

Cf. A187395.

Programs

  • Mathematica
    r=4+10^(1/2); s=-2+10^(1/2);
    Table[Floor[r*n],{n,1,80}]  (* A187395 *)
    Table[Floor[s*n],{n,1,80}]  (* A187396 *)
  • Python
    from sympy import integer_nthroot
    def A187396(n): return integer_nthroot(10*n**2,2)[0]-2*n # Chai Wah Wu, Mar 17 2021

Formula

a(n) = floor(s*n), where s = -2 + sqrt(10).

Extensions

Edited by Clark Kimberling, Mar 17 2021