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.

A188383 Positions of 1 in the zero-one sequence [nr+3r]-[nr]-[3r], where r=1/sqrt(2).

Original entry on oeis.org

7, 14, 24, 31, 41, 48, 55, 65, 72, 82, 89, 96, 106, 113, 123, 130, 140, 147, 154, 164, 171, 181, 188, 195, 205, 212, 222, 229, 239, 246, 253, 263, 270, 280, 287, 294, 304, 311, 321, 328, 335, 345, 352, 362, 369, 379, 386, 393, 403, 410, 420, 427, 434, 444, 451, 461, 468, 478, 485, 492, 502, 509, 519, 526, 533, 543, 550
Offset: 1

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Author

Clark Kimberling, Mar 30 2011

Keywords

Comments

See A187950.
Positions of 1 in the {0->000, 11->null}-transform of the Sturmian word A080764; see A286996. Also, a(n) - a(n-1) is in {7,10} for n >= 1, and a(n)/n -> 4 + 3*sqrt(2). - Clark Kimberling, May 20 2017

Crossrefs

Cf. A187950.

Programs

  • Mathematica
    r=2^(-1/2); k=3;
    t=Table[Floor[n*r+k*r]-Floor[n*r]-Floor[k*r], {n,1,220}]
    Flatten[Position[t,1] ] (* A188383 *)
  • Python
    from _future_ import division
    from gmpy2 import isqrt
    A188383_list = [n for n in range(1,10**6) if isqrt((n+3)**2//2) - isqrt(n**2//2) == 3] # Chai Wah Wu, Oct 08 2016