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.

A177738 a(n) = floor( (x^n - x^(-n)) / (x - x^(-1)) ) where x = Pi-2.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 8, 9, 11, 13, 15, 17, 20, 23, 26, 30, 35, 40, 46, 52, 60, 69, 78, 90, 103, 117, 134, 153, 175, 199, 228, 260, 297, 339, 387, 442, 505, 576, 658, 751, 858, 979, 1118, 1277, 1457, 1664, 1900, 2169, 2476, 2826
Offset: 0

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Author

Roger L. Bagula, May 12 2010

Keywords

Comments

The ratio a(n+1)/a(n) approaches Pi-2 as n approaches infinity, and is lower than even Salem polynomial expansions based on A073011.
The idea is the emulation of quadratic beta integer domains using a transcendental number base with a ratio below A073011.

Crossrefs

Programs

  • Mathematica
    Clear[a, n, b]; b = Pi - 2; a[n_] = (b^n - b^(-n))/(b - b^(-1));
    Table[Floor[a[n]], {n, 0, 50}]

Extensions

Undefined terminology removed from the definition - The Assoc. Eds. of the OEIS, May 14 2010